Index: source/blender/editors/space_buttons/buttons_header.c
===================================================================
--- source/blender/editors/space_buttons/buttons_header.c	(revision 51390)
+++ source/blender/editors/space_buttons/buttons_header.c	(working copy)
@@ -105,6 +105,7 @@
 	uiBlock *block;
 	uiBut *but;
 	int xco, yco = 2;
+	int butwidth;
 
 	buttons_context_compute(C, sbuts);
 	
@@ -112,18 +113,22 @@
 	uiBlockSetHandleFunc(block, do_buttons_buttons, NULL);
 	
 	xco = ED_area_header_switchbutton(C, block, yco);
+	xco += 4;
 	
 	uiBlockSetEmboss(block, UI_EMBOSS);
 
-	xco -= UI_UNIT_X;
+	butwidth = (ar->winx - (xco + (UI_UNIT_X / 2))) / HEADER_BUTS_NUM;
+	if (butwidth < HEADER_BUT_MIN_WIDTH) butwidth = HEADER_BUT_MIN_WIDTH;
 
+	xco -= butwidth;
+
 	/* Default panels */
 
 	uiBlockBeginAlign(block);
 
 #define BUTTON_HEADER_CTX(_ctx, _icon, _tip) \
 	if (sbuts->pathflag & (1 << _ctx)) { \
-		but = uiDefIconButS(block, ROW, B_CONTEXT_SWITCH, _icon, xco += BUT_UNIT_X, yco, BUT_UNIT_X, UI_UNIT_Y, &(sbuts->mainb), 0.0, (float)_ctx, 0, 0, TIP_(_tip)); \
+		but = uiDefIconButS(block, ROW, B_CONTEXT_SWITCH, _icon, xco += butwidth, yco, butwidth, UI_UNIT_Y, &(sbuts->mainb), 0.0, (float)_ctx, 0, 0, TIP_(_tip)); \
 		uiButClearFlag(but, UI_BUT_UNDO); \
 	} (void)0
 
Index: source/blender/editors/space_buttons/buttons_intern.h
===================================================================
--- source/blender/editors/space_buttons/buttons_intern.h	(revision 51390)
+++ source/blender/editors/space_buttons/buttons_intern.h	(working copy)
@@ -59,6 +59,12 @@
 #define BUTS_SENS_STATE     512
 #define BUTS_ACT_STATE      1024
 
+
+/* header */
+#define HEADER_BUTS_NUM		11
+#define HEADER_BUT_MIN_WIDTH	10
+
+
 /* context data */
 
 typedef struct ButsContextPath {