Mono 2.0 has been released – with Firebird .Net Provider support
Mono’s 2.0 grand release has finally arrived.
See detailed release notes covering both the 2.0 launch and the changes since Mono 1.9.
Or you can go directly and download Mono 2.0 for your platform.
Also you must use Firebird DotNet Provider 2.5 with Firebird 2.1 .
Here are my notes on Ubuntu Intrepid