> Note added - I am using Firebird 1.5 together with C++ Builder 6.
>
> I checked point 3 - but there was not any improvement. I have
> commented this config variable and I am using the default space for
> udf libraries - i.e. /UDF unders installation directory. This should
> not be the configuration issue, because all has worked OK with the
> previous version of dll.
>
> Well - there is one strange thing - my new dll I have tried to
> compile with FB (not Interbase) includes and libs, but I have not
> ib_util.lib available (I should use one from Interbase, from the
> other hand - it I tried to compile without this lib, I have receievd
> error message, that ib_alloc_mem cann't be resolved - so - why there
> is ib_util_ms.lib for Microsoft build utilities and no ib_util.lib
> for Borland C++ build utilities)... So - what should be the correct
> action in this case?

You need to find how to link againts ib_util.dll. If you can't - use
dynamic loading.

Note, 'module name or entrypoint could not be found' error is raised by
Firebird also if it can't load module because this module have unresolved
dependencies. IIRC, Borland C++'s dlls have some dependency from
Borland's run-time support libraries.

Regards,
Vlad