Mark,

If it's a Fortran DLL you might try using all uppercase or all lowercase in the Declare.

>Thanks for the answers, The DLL is not build by me (BTW It's build in MS Fortran) so I don't know exactly what's wrong within the DLL but I figured out it's a combination of different things. The creator is notified and will look into it. At least I learned why the declare doesn't give an error while a declare in WIN32API does!