Index: /trunk/src/VBox/Main/VirtualBoxCallbackImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/VirtualBoxCallbackImpl.cpp	(revision 29452)
+++ /trunk/src/VBox/Main/VirtualBoxCallbackImpl.cpp	(revision 29453)
@@ -167,5 +167,14 @@
         return S_OK;
 
+#if defined(RT_OS_WINDOWS) && defined(RT_ARCH_AMD64)
+    /* Letting this thru crashes in VariantInit, probably because the last
+       parameter is a BYTE pointer.  For now, don't let it thru to python or
+       what other users this class might have. */
+    /** @todo Figure if this applies to 32-bit hosts as well. */
+    /** @todo Find better solution? */
+    return VBOX_E_DONT_CALL_AGAIN;
+#else
     return mConsoleCallback->OnMousePointerShapeChange(visible, alpha, xHot, yHot, width, height, shape);
+#endif
 }