OPn NT4 the clist shwlwapi test fails on the first call to SHLWAPI_166 (on line 478 here). That call triggers wat looks like an internal check which pops up a nice error window:
Debug Error!
Program: ...dlls\shlwapi\tests\Output\Win32_MSVC_Headers\shlwapi_test.exe Module: File: i386\chkesp.c Line: 42
The value of ESP was not properly saved accross a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a differen calling convention.
(Press Retry to debug the application)
Could it be a problem with the way IDummyStream is declared? Maybe the virtual function pointer is off? I noticed that no 'COM' macro was used which sees a bit strange. Or maybe it's a problem with the prototype of SHLWAPI_166?
Could someone more knowledgeable with shlwapi investigate this?