Access denied to TaminoAPI

Hi,
I’m currently using .NET web services that use internally Tamino Api for .NET. I have a ASP.NET web project that makes the calls to the web services.
If I include the DLL web services as static references, all works fine. But when the calls are made through the web, I get the following exception:

Access denied: 'TaminoAPI’

just before the Tamino API is used.
Is this related to user access and windows authentication in .NET web applications? I’m currently using ‘anonymous access’ and ‘integrated windows authentication’.
I would be very grateful if someone could help.

Thanks,

Enric

Is that all the text from the exception or is there anything else?