D-Link DI-514 and L2TP VPN Connection

I am trying to connect to my company VPN (ISA L2TP/IPSec) through my
d-link di514 router. If I connect straight to the cable modem I get
in without a problem. If I try through the router (and also I also
tried a Linksys wireless router) I receive the message: "Error 788:
The L2TP connection attempt failed because the security layer could
not negotiate compatible parameters with the remote computer".

VPN pass through is enabled on the router.

Any assistance would be appreciated.

Daniel