PPTP, GRE 47 passthrough on a Netgear router

[dbrb2]

Hi... I've been having some issues with VPN connection to my work via my Netgear router. Their tech support people told me:

"

...you are using the Nortel VPN
client. The Nortel client uses a
encapsulation with the PPTP protocol. Because of the encryption attached
to the PPTP protocol, the router cannot establish a VPN connection. This
encapsulation is called GRE47. The particular router/modem that you have
does not support GRE47. This explains why you can connect using the
university's wifi and other networks and not the router

"

But the datasheet for our router (DG834G) specifies that it supports IPSec and PPTP and L2TP VPN passthrough:

"
NAT traversal (VPN passthrough) for IPSec, PPTP and L2TP VPNs
"

Wikipedia states:

"PPTP works by sending a regular PPP session to the peer with the
Generic Routing Encapsulation (GRE) protocol"

So the router says it supports PPTP, and wikipedis says that means it supports GRE 47 protocol, but Netgear tech support state that it does not. What is the truth here?

If they are right, can anyone suggest alternative hardware (wifi, router, ADSL modem)

Cheers,

Ben