jaybird can't connect dbs diablo jdk16

[Matthias]

Hello,
here is a freebsd 7.1 machine with Diablo JavaSE 1.6.0_07_b02 and a 
firebird 2.0.3 db.
 From this server I can't connect any firebird db neither the local one 
nor the lan dbs with jaybird2.1.6.
I get the error message:GDS Exception. 335544721 Unable to complete 
network request to host $hostname. $hostname is the orginal given name.
IP addresses or fqdns create the same error message.
First thought: address resolving! I've checked firewall, name resolving 
- everything seems to be ok.
The same binaries and ajybird drivers are running without problems on 
win and mac os, connecting to _every_ db.
Unfortunately i have only a second freebsd 6.2 server with diablo jdk 
1.5 ; but compiled for 1.5 it runs without problems too; the same on 
Solaris10.
Only this machine has connection problems with jaybird. The local db is 
reachable from other applications; the local gbak can connect too.

Maybe someone has a clue or expierence with this combo.

Matthias