Probably triggered by Rob's five rpcrt4 patches on July 3rd, who knows, perhaps the removal of the memset in http://www.winehq.org/pipermail/wine-cvs/2008-July/045025.html Rob, can you have a look? http://kegel.com/wine/valgrind/logs-2008-07-04/vg-oleaut32_tmarshal-diff.txt
e.g.
+ Conditional jump or move depends on uninitialised value(s) + at VARIANT_ValidateType (variant.c:545) + by VariantClear (variant.c:598) + by VARIANT_UserUnmarshal (usrmarshal.c:594) + by NdrUserMarshalUnmarshall (ndr_marshall.c:3772) + by ComplexUnmarshall (ndr_marshall.c:2439) + by NdrComplexArrayUnmarshall (ndr_marshall.c:3505) + by PointerUnmarshall (ndr_marshall.c:1302) + by EmbeddedPointerUnmarshall (ndr_marshall.c:1622) + by NdrSimpleStructUnmarshall (ndr_marshall.c:2059) + by PointerUnmarshall (ndr_marshall.c:1302) + by NdrPointerUnmarshall (ndr_marshall.c:1886) + by IDispatch_RemoteInvoke_Stub (oleaut32_oaidl_p.c:838) + by CStdStubBuffer_Invoke (cstub.c:433) + by RPC_ExecuteCall (rpc.c:1392) + by apartment_wndproc (compobj.c:547) + by ??? (library.h:163) + by call_window_proc (winproc.c:457) + by WINPROC_CallProcAtoW (winproc.c:1011) + by WINPROC_call_window (winproc.c:2209) + by DispatchMessageA (message.c:3067) + Uninitialised value was created by a client request + at mark_block_uninitialized (heap.c:164) + by RtlAllocateHeap (heap.c:1239) + by IMalloc_fnAlloc (ifs.c:186) + by CoTaskMemAlloc (ifs.c:562) + by NdrOleAllocate (ndr_ole.c:359) + by NdrAllocate (ndr_marshall.c:381) + by NdrComplexArrayUnmarshall (ndr_marshall.c:3498) + by PointerUnmarshall (ndr_marshall.c:1302) + by EmbeddedPointerUnmarshall (ndr_marshall.c:1622) + by NdrSimpleStructUnmarshall (ndr_marshall.c:2059) + by PointerUnmarshall (ndr_marshall.c:1302) + by NdrPointerUnmarshall (ndr_marshall.c:1886) + by IDispatch_RemoteInvoke_Stub (oleaut32_oaidl_p.c:838) + by CStdStubBuffer_Invoke (cstub.c:433) + by RPC_ExecuteCall (rpc.c:1392) + by apartment_wndproc (compobj.c:547) + by ??? (library.h:163) + by call_window_proc (winproc.c:457) + by WINPROC_CallProcAtoW (winproc.c:1011) + by WINPROC_call_window (winproc.c:2209)
...