Tricky C code

We have a static library project linked into a DLL. For years, this static library does not require initialization/unitialization code. This time a new feature is added that requires the initialization and cleanup. So we have to call functions when the DLL is attached/detached to the process.

The original DLL does not have a DllMain. We got one by having VC++ create for us, and it did. We did this by creating a new DLL project and copy the function into ours:

BOOL APIENTRY DllMain( HMODULE hModule,
                     DWORD ul_reason_for_call,
                     LPVOID lpReserved)
{
  switch (ul_reason_for_call)
  {
     case DLL_PROCESS_ATTACH:
     case DLL_THREAD_ATTACH:
     case DLL_THREAD_DETACH:
     case DLL_PROCESS_DETACH:
  }
  return TRUE;
}

It was easy to paste code. Now we invoke functions:

 case DLL_PROCESS_ATTACH:
    InitMyLib();
    break;
  case DLL_THREAD_ATTACH:
  case DLL_THREAD_DETACH:
  case DLL_PROCESS_DETACH:
   TerminateMyLib();
   break;

Unfortunately did not work as we expected. Does anyone see the problem?