VPN connection

I have a remote user using Cisco VPN client 4.6. He CAN authenticate successfully, I see him logged in on the server log, yet he cannot connect to the intranet or to his exchange server. His internet connection is fine until the VPN connection is established. I tried changing the transport method from IPsec over UDP to TCP, tried disabling transparent tunneling, reinstalled the connection entry, and finaly reinstalled the client. No luck.
Any suggestions?