Index: /trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp	(revision 29984)
+++ /trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp	(revision 29985)
@@ -225,5 +225,5 @@
     {
         /* We can't probe kernel memory ranges, so pretend it's one big region. */
-        aRegions[idxRegion].GCRegionAddr = (RTGCPTR64)pBaseAddress;
+        aRegions[idxRegion].GCRegionAddr = (RTGCPTR64)(PVOID)pBaseAddress;  /* stupid cast to avoid sign extension */
         aRegions[idxRegion].cbRegion     = dwModuleSize;
         idxRegion++;