> So... I would like to know if the Jaybird 2.1.1 fully supports the
> Firebird 1.5 Server. Is there any problem changing the driver to the
> new 2.1.x series when all my .fdb files was created using the 1.5.x
> driver version?

There should be no issues when using Jaybird 2.1.1 with Firebird 1.5 server.
The driver connects to the database either via TCP sockets and the protocol
did not change since FB 0.9.x or via the client library
(fbclient.dll/fbembed.dll) and the API also did not change.

Roman