Index: /trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp	(revision 29989)
+++ /trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp	(revision 29990)
@@ -225,5 +225,9 @@
     {
         /* We can't probe kernel memory ranges, so pretend it's one big region. */
-        aRegions[idxRegion].GCRegionAddr = (RTGCPTR64)(PVOID)pBaseAddress;  /* stupid cast to prevent sign extension */
+#ifdef GC_ARCH_BITS == 64
+        aRegions[idxRegion].GCRegionAddr = (RTGCPTR64)pBaseAddress;
+#else
+        aRegions[idxRegion].GCRegionAddr = (RTGCPTR32)pBaseAddress;
+#endif
         aRegions[idxRegion].cbRegion     = dwModuleSize;
         idxRegion++;