Thanks a lot for your comments!

I tried the 32-bit ODBC manager (it's really stunning that there are two of them!) and was able to access the database through the DSN successfully.

Anyway, I followed your suggestion and switched to the Firebird .NET data provider. Works like a charm!

Thanks again,
Anne

--- In firebird-support@yahoogroups.com, "Mark Rotteveel" <Avalanche1979@...> wrote:
>
> Windows 64 bits has two(!) ODBC managers, the one you can easily access is the 64 bit variant, the other one you need to locate yourself (I believe in the SysWOW64 folder). As far as I know the Firebird ODBC driver is only 32 bits, so you will need to configure it using the 32 bits ODBC manager.
>
> The problem could also be that your application is 64 bits, it is impossible for a 64 bit application to directly use a 32 bit ODBC driver (Windows does not allow 64 bit programs to load 32 bit drivers, DLLs and such).
>
> Yet another cause could be that the SysWOW64 folder does not contain the gds32.dll: confusingly onder Windows 64 the System32 folder contains the 64 bit DLLs and the SysWOW64 contains the 32 bit DLLs that are in System32 on a 32bit system. Also make sure you use the 32 bit variant of fbclient.dll as the gds32.dll.
>
> My advice: if you can, avoid using ODBC, especially on 64 bit Windows.
>
> Mark
>