Index: /trunk/src/VBox/Devices/Graphics/DevVGA.cpp
===================================================================
--- /trunk/src/VBox/Devices/Graphics/DevVGA.cpp	(revision 33039)
+++ /trunk/src/VBox/Devices/Graphics/DevVGA.cpp	(revision 33040)
@@ -6163,7 +6163,11 @@
 {
     int         maxPage;
-
+    int         bpl;
+    
+
+    /* For 4bpp modes, the planes are "stacked" on top of each other. */
+    bpl = pMode->info.BytesPerScanLine * pMode->info.NumberOfPlanes;
     /* The "number of image pages" is really the max page index... */
-    maxPage = pThis->vram_size / (pMode->info.YResolution * pMode->info.BytesPerScanLine) - 1;
+    maxPage = pThis->vram_size / (pMode->info.YResolution * bpl) - 1;
     Assert(maxPage >= 0);
     if (maxPage > 255)