Index: source/blender/editors/screen/area.c
===================================================================
--- source/blender/editors/screen/area.c (revision 26600)
+++ source/blender/editors/screen/area.c (working copy)
@@ -592,10 +592,10 @@ static void region_azone_add(ScrArea *sa, ARegion *ar, int alignment)
 static int rct_fits(rcti *rect, char dir, int size)
 {
 	if(dir=='h') {
-		return rect->xmax-rect->xmin - size;
+		return rect->xmax-rect->xmin +1 - size;
 	}
 	else { // 'v'
-		return rect->ymax-rect->ymin - size;
+		return rect->ymax-rect->ymin + 1 - size;
 	}
 }
 
Index: source/blender/editors/screen/screen_edit.c
===================================================================
--- source/blender/editors/screen/screen_edit.c (revision 26600)
+++ source/blender/editors/screen/screen_edit.c (working copy)
@@ -251,12 +251,12 @@ int scredge_is_horizontal(ScrEdge *se)
 	return (se->v1->vec.y == se->v2->vec.y);
 }
 
-ScrEdge *screen_find_active_scredge(bScreen *sc, int mx, int my)
+ScrEdge *screen_find_active_scredge(bScreen *sc, int winsizex, int winsizey, int mx, int my)
 {
 	ScrEdge *se;
 	
 	for (se= sc->edgebase.first; se; se= se->next) {
-		if (scredge_is_horizontal(se)) {
+		if (scredge_is_horizontal(se) && se->v1->vec.y < winsizey-1 && se->v1->vec.y > 0) {
 			short min, max;
 			min= MIN2(se->v1->vec.x, se->v2->vec.x);
 			max= MAX2(se->v1->vec.x, se->v2->vec.x);
@@ -264,7 +264,7 @@ ScrEdge *screen_find_active_scredge(bScreen *sc, int mx, int my)
 			if (abs(my-se->v1->vec.y)<=2 && mx>=min && mx<=max)
 				return se;
 		} 
-		else {
+		else if(se->v1->vec.x < winsizex-1 && se->v1->vec.x > 0){
 			short min, max;
 			min= MIN2(se->v1->vec.y, se->v2->vec.y);
 			max= MAX2(se->v1->vec.y, se->v2->vec.y);
@@ -631,8 +631,8 @@ static void screen_test_scale(bScreen *sc, int winsizex, int winsizey)
 		sv->vec.y -= min[1];
 	}
 	
-	sizex= max[0]-min[0];
-	sizey= max[1]-min[1];
+	sizex= max[0]-min[0]+1;
+	sizey= max[1]-min[1]+1;
 	
 	if(sizex!= winsizex || sizey!= winsizey) {
 		facx= winsizex;
@@ -647,14 +647,14 @@ static void screen_test_scale(bScreen *sc, int winsizex, int winsizey)
 			sv->vec.x+= AREAGRID-1;
 			sv->vec.x-=  (sv->vec.x % AREAGRID); 
 			
-			CLAMP(sv->vec.x, 0, winsizex);
+			CLAMP(sv->vec.x, 0, winsizex-1);
 			
 			tempf= ((float)sv->vec.y )*facy;
 			sv->vec.y= (short)(tempf+0.5);
 			sv->vec.y+= AREAGRID-1;
 			sv->vec.y-=  (sv->vec.y % AREAGRID); 
 			
-			CLAMP(sv->vec.y, 0, winsizey);
+			CLAMP(sv->vec.y, 0, winsizey-1);
 		}
 	}
 	
@@ -663,7 +663,11 @@ static void screen_test_scale(bScreen *sc, int winsizex, int winsizey)
 	
 	/* make each window at least HEADERY high */
 	for(sa= sc->areabase.first; sa; sa= sa->next) {
-		int headery= HEADERY+1;
+		int headery= HEADERY-1;
+		
+		/* adjust headery if verts along the edge of window */
+		if(sa->v1->vec.y > 0) headery++;
+		if(sa->v2->vec.y < winsizey-1) headery++;
 		
 		if(sa->v1->vec.y+headery > sa->v2->vec.y) {
 			/* lower edge */
@@ -1164,7 +1168,7 @@ static void screen_cursor_set(wmWindow *win, wmEvent *event)
 		}
 	}
 	else {
-		ScrEdge *actedge= screen_find_active_scredge(win->screen, event->x, event->y);
+		ScrEdge *actedge= screen_find_active_scredge(win->screen, win->sizex, win->sizey, event->x, event->y);
 		
 		if (actedge) {
 			if(scredge_is_horizontal(actedge))
Index: source/blender/editors/screen/screen_intern.h
===================================================================
--- source/blender/editors/screen/screen_intern.h (revision 26600)
+++ source/blender/editors/screen/screen_intern.h (working copy)
@@ -47,7 +47,7 @@ void		removedouble_scrverts(bScreen *sc);
 void		removedouble_scredges(bScreen *sc);
 void		removenotused_scredges(bScreen *sc);
 int			scredge_is_horizontal(ScrEdge *se);
-ScrEdge		*screen_find_active_scredge(bScreen *sc, int mx, int my);
+ScrEdge		*screen_find_active_scredge(bScreen *sc, int winsizex, int winsizey, int mx, int my);
 
 AZone		*is_in_area_actionzone(ScrArea *sa, int x, int y);
 
Index: source/blender/editors/screen/screen_ops.c
===================================================================
--- source/blender/editors/screen/screen_ops.c (revision 26600)
+++ source/blender/editors/screen/screen_ops.c (working copy)
@@ -773,9 +773,11 @@ typedef struct sAreaMoveData {
 	char dir;
 } sAreaMoveData;
 
-/* helper call to move area-edge, sets limits */
-static void area_move_set_limits(bScreen *sc, int dir, int *bigger, int *smaller)
+/* helper call to move area-edge, sets limits
+need window size to make adjustments for verts at window edge*/
+static void area_move_set_limits(bScreen *sc, int dir, int winsizex, int winsizey, int *bigger, int *smaller)
 {
+	int areamin;
 	ScrArea *sa;
 	
 	/* we check all areas and test for free space with MINSIZE */
@@ -783,7 +785,12 @@ static void area_move_set_limits(bScreen *sc, int dir, int *bigger, int *smaller
 	
 	for(sa= sc->areabase.first; sa; sa= sa->next) {
 		if(dir=='h') {
-			int y1= sa->v2->vec.y - sa->v1->vec.y-AREAMINY;
+			int y1;
+			areamin=AREAMINY-1;
+			if(sa->v1->vec.y > 0) areamin++;
+			if(sa->v2->vec.y < winsizey-1) areamin++;
+			
+			y1= sa->v2->vec.y - sa->v1->vec.y-areamin;
 			
 			/* if top or down edge selected, test height */
 			if(sa->v1->flag && sa->v4->flag)
@@ -792,7 +799,12 @@ static void area_move_set_limits(bScreen *sc, int dir, int *bigger, int *smaller
 				*smaller= MIN2(*smaller, y1);
 		}
 		else {
-			int x1= sa->v4->vec.x - sa->v1->vec.x-AREAMINX;
+			int x1;
+			areamin=AREAMINX-1;
+			if(sa->v1->vec.y > 0) areamin++;
+			if(sa->v2->vec.y < winsizex-1) areamin++;
+			
+			x1= sa->v4->vec.x - sa->v1->vec.x-areamin;
 			
 			/* if left or right edge selected, test width */
 			if(sa->v1->flag && sa->v2->flag)
@@ -808,6 +820,7 @@ static void area_move_set_limits(bScreen *sc, int dir, int *bigger, int *smaller
 static int area_move_init (bContext *C, wmOperator *op)
 {
 	bScreen *sc= CTX_wm_screen(C);
+	wmWindow *win= CTX_wm_window(C);
 	ScrEdge *actedge;
 	sAreaMoveData *md;
 	int x, y;
@@ -817,7 +830,7 @@ static int area_move_init (bContext *C, wmOperator *op)
 	y= RNA_int_get(op->ptr, "y");
 	
 	/* setup */
-	actedge= screen_find_active_scredge(sc, x, y);
+	actedge= screen_find_active_scredge(sc, win->sizex, win->sizey, x, y);
 	if(actedge==NULL) return 0;
 	
 	md= MEM_callocN(sizeof(sAreaMoveData), "sAreaMoveData");
@@ -830,7 +843,7 @@ static int area_move_init (bContext *C, wmOperator *op)
 	select_connected_scredge(sc, actedge);
 	/* now all vertices with 'flag==1' are the ones that can be moved. */
 	
-	area_move_set_limits(sc, md->dir, &md->bigger, &md->smaller);
+	area_move_set_limits(sc, md->dir, win->sizex, win->sizey, &md->bigger, &md->smaller);
 	
 	return 1;
 }
@@ -841,6 +854,8 @@ static void area_move_apply_do(bContext *C, int origval, int delta, int dir, int
 	wmWindow *win= CTX_wm_window(C);
 	bScreen *sc= CTX_wm_screen(C);
 	ScrVert *v1;
+	int doredraw= 0;
+	int oldval;
 	
 	delta= CLAMPIS(delta, -smaller, bigger);
 	
@@ -848,31 +863,43 @@ static void area_move_apply_do(bContext *C, int origval, int delta, int dir, int
 		if (v1->flag) {
 			/* that way a nice AREAGRID  */
 			if((dir=='v') && v1->vec.x>0 && v1->vec.x<win->sizex-1) {
+				oldval = v1->vec.x;
 				v1->vec.x= origval + delta;
-				if(delta != bigger && delta != -smaller) v1->vec.x-= (v1->vec.x % AREAGRID);
+				if(delta != bigger && delta != -smaller)
+				{
+					v1->vec.x-= (v1->vec.x % AREAGRID);
+					v1->vec.x=CLAMPIS(v1->vec.x, origval-smaller, origval+bigger);
+				}
+				if(oldval != v1->vec.x)
+					doredraw=1;
 			}
 			if((dir=='h') && v1->vec.y>0 && v1->vec.y<win->sizey-1) {
+				oldval = v1->vec.y;
 				v1->vec.y= origval + delta;
 				
-				v1->vec.y+= AREAGRID-1;
-				v1->vec.y-= (v1->vec.y % AREAGRID);
-				
-				/* prevent too small top header */
-				if(v1->vec.y > win->sizey-AREAMINY)
-					v1->vec.y= win->sizey-AREAMINY;
+				if(delta != bigger && delta != -smaller)
+				{
+					v1->vec.y-= (v1->vec.y % AREAGRID);
+					v1->vec.y=CLAMPIS(v1->vec.y, origval-smaller, origval+bigger);
+				}
+				if(oldval != v1->vec.y)
+					doredraw=1;
 			}
 		}
 	}
 #ifdef WM_FAST_DRAW
 	{
-		ScrArea *sa;
-		for(sa= sc->areabase.first; sa; sa= sa->next)
-			if(sa->v1->flag || sa->v2->flag || sa->v3->flag || sa->v4->flag)
-				ED_area_tag_redraw(sa);
+		if (doredraw) {
+			ScrArea *sa;
+			for(sa= sc->areabase.first; sa; sa= sa->next)
+				if(sa->v1->flag || sa->v2->flag || sa->v3->flag || sa->v4->flag)
+					ED_area_tag_redraw(sa);
+		}
 	}
 
 #endif
-	WM_event_add_notifier(C, NC_SCREEN|NA_EDITED, NULL); /* redraw everything */
+	if (doredraw)
+		WM_event_add_notifier(C, NC_SCREEN|NA_EDITED, NULL); /* redraw everything */
 }
 
 static void area_move_apply(bContext *C, wmOperator *op)
@@ -1171,6 +1198,7 @@ static void area_split_exit(bContext *C, wmOperator *op)
 static int area_split_invoke(bContext *C, wmOperator *op, wmEvent *event)
 {
 	sAreaSplitData *sd;
+	wmWindow *win= CTX_wm_window(C);
 	
 	if(event->type==EVT_ACTIONZONE_AREA) {
 		sActionzoneData *sad= event->customdata;
@@ -1214,7 +1242,7 @@ static int area_split_invoke(bContext *C, wmOperator *op, wmEvent *event)
 		
 		/* do the split */
 		if(area_split_apply(C, op)) {
-			area_move_set_limits(CTX_wm_screen(C), dir, &sd->bigger, &sd->smaller);
+			area_move_set_limits(CTX_wm_screen(C), dir, win->sizex, win->sizey, &sd->bigger, &sd->smaller);
 			
 			/* add temp handler for edge move or cancel */
 			WM_event_add_modal_handler(C, op);
Index: source/blender/makesdna/DNA_screen_types.h
===================================================================
--- source/blender/makesdna/DNA_screen_types.h (revision 26600)
+++ source/blender/makesdna/DNA_screen_types.h (working copy)
@@ -180,7 +180,7 @@ typedef struct ARegion {
 #define AREAGRID	4
 #define AREAMINX	32
 #define HEADERY		26
-#define AREAMINY	(HEADERY+EDGEWIDTH)
+#define AREAMINY	HEADERY
 
 #define HEADERDOWN	1
 #define HEADERTOP	2