Index: source/blender/editors/screen/area.c
===================================================================
--- source/blender/editors/screen/area.c	(Revision 21841)
+++ source/blender/editors/screen/area.c	(Arbeitskopie)
@@ -1242,6 +1242,7 @@
 
 	/* before setting the view */
 	if(vertical) {
+		/* only allow scrolling in x axis */
 		v2d->keepofs |= V2D_LOCKOFS_X;
 		v2d->keepofs &= ~V2D_LOCKOFS_Y;
 		
@@ -1249,8 +1250,8 @@
 		y= MAX2(-y, -v2d->cur.ymin);
 	}
 	else {
-		v2d->keepofs &= ~V2D_LOCKOFS_X;
-		v2d->keepofs |= V2D_LOCKOFS_Y;
+		/* allow scrolling on both axes */
+		v2d->keepofs &= ~(V2D_LOCKOFS_X|V2D_LOCKOFS_Y);
 		
 		// don't jump back when panels close or hide
 		x= MAX2(x, v2d->cur.xmax);