Connecting to VPN server from Linux behind Watchguard x500

Hi...i'm trying to establish a vpn connection from my linux box (ubuntu
server 6.06) to my vpn router at home...if I connect with my windows
machine everything is normal and i get two lines in the watchguard log:


09/27/06 16:35 kernel: ip_masq_pptp(): Req outcall PPTP sess
192.168.0.122 -> Call ID 4000 -> B474.

09/27/06 16:35 kernel: ip_masq_pptp(): Estab outcall PPTP sess
192.168.0.122 -> Call ID B474 -> 4000.

When I try to connect with the pptp client in linux I get this repeated
several times from the debug output of pptp:

sent [LCP ConfReq id=0x1
]

and I get this repeated as many times as the above in the watchguard
log

09/27/06 16:30 kernel: ip_fw_masq_gre(): Outbound GRE to
has no masq table entry.

Does anyone have any ideas about this? Perhaps this is not a firewall
issue, but maybe someone can shed some light on what the firebox log is
telling me.

Thanks!!