It sounds like DBD::Sybase is trying to load the Sybase DLLs and perhaps cannot find them all.

On UNIX, this would be because the LD_LIBRARY_PATH variable needs to be set, as well as the SYBASE one.

On WinNT, the analagous variable is PATH. It's possible that the order of directories in the Path is incorrect and a non-Sybase library with the same name as a Sybase one is being found first.

On UNIX, for instance, the library name, libintl.so occurs in both /usr/lib and in $SYBASE/lib, so their order within LD_LIBRARY_PATH matters.

If you run the webserver as LocalSystem, make sure that the sybase BIN directory is in the right location in the Global PATH; if you run it as an unpriviledged user, log in as that user and make sure it is in that user's User PATH (or just add it to the global PATH anyway).

Update: I had another thought. Perhaps DBD::Sybase is loading earlier than you expect for some reason (like before the BEGIN block has a chance to change SYBASE)?

dmm

If you GIVE a man a fish you feed him for a day
But, TEACH him to fish and you feed him for a lifetime