F5 client on Ubuntu 9.04 + Firefox

I'm using the F5 network client on Ubuntu 9.04 32-bit and Firefox 3.5.7/3.0.17. I can get the the client to connect, but after the connection is established I have no network access at all, except to the local net. Web pages don't work and according to the connection window data gets sent but nothing is received after the initial 190 bytes or so.) Name servers are set up, routing looks okay (although I am not an expert), yet sent packets don't escape the computer (e.g. the router lights don't flicker when I ping an ip address outside the localnet.) This works fine on a Windows XP machine running Firefox 3.0 on the same network.

 

 

Any clues?