Hi :)
There's something else: the connections string is wrong:
"jdbc:firebirdsql://localhost/3050:Ibaccess.gdb" should be

"jdbc:firebirdsql:localhost/3050:drive:/path/to/Ibaccess.gdb" (Windows)
or
"jdbc:firebirdsql:localhost/3050:/path/to/Ibaccess.gdb" (Linux & co)

Ciao
Luca