Think I may have cracked it! its amazing what posting a problem on hear can do even without replies
any who the 2600 has 3 NIC's so in /etc/xen/xend-config.sxp I changed
(network-script network-bridge)
to
(network-script 'network-bridge netdev=eth0')
So far so good if I leave no more messages it will probably be working. If it does work for the next day or to I will try to remember to come back and mark it as solved