- closing the user prefs accessed the temp screen after removing it.

- colorband drawing could use un-initialized vars (probably wouldnt crash)

source/blender/editors/interface/interface_draw.c

@@ -698,7 +698,7 @@ void ui_draw_but_COLORBAND(uiBut *but, uiWidgetColors *wcol, rcti *rect)
 	float x1, y1, sizex, sizey;
 	float dx, v3[2], v1[2], v2[2], v1a[2], v2a[2];
 	int a;
-	float pos, colf[4];
+	float pos, colf[4]= {0,0,0,0}; /* initialize incase the colorband isnt valid */
 		
 	coba= (ColorBand *)(but->editcoba? but->editcoba: but->poin);
 	if(coba==NULL) return;

source/blender/editors/screen/screen_edit.c

@@ -1124,13 +1124,14 @@ void ED_screen_exit(bContext *C, wmWindow *window, bScreen *screen)
 	/* mark it available for use for other windows */
 	screen->winid= 0;
 	
+	/* before deleting the temp screen or we get invalid access */
+	CTX_wm_window_set(C, prevwin);
+	
 	/* if temp screen, delete it */
 	if(screen->full == SCREENTEMP) {
 		Main *bmain= CTX_data_main(C);
 		free_libblock(&bmain->screen, screen);
 	}
-	
-	CTX_wm_window_set(C, prevwin);
 }
 
 /* *********************************** */