So now you know my intention - and I believe that the code reflects that. I'm guessing that the key might be that the DLL gets unloaded "too soon" so that we get a seg fault by invoking code that is no longer in memory. But as you have discovered - this is very problematic to track down and could be a subtle error of my own, an error in the language support system (loading/unloading DLLS). Overzealous optimization on the compiler's part or something else entirely. Sorry I can't be of more help. Good Luck Robert Ramey