Hi,
You are trying to access some cororate servers of yours through a cisco VPN client oevr a DSL connection..is my understanding corect?
Does your ISP uses PPPoE for their connectivity?
In yes, they might be installing the PPPoE adapeter on the client machine which might be creating problems.It changes the native IP stack whch can screw up the working.
I have faced similar problems with my DSL connection..the solution was to uninstall the PPPoE stack and place a DSL router in between the client machin and the modem. Now the headache of PPPoE gets shifted from the client machine to the DSL router .
regards,
jimmy.