I've just figured my problem out re Vista as in a separate post.
Google
Vista unidentified network problems.
watch the 2,240,000 hits come up.
begin 2 days of messing about.
OK basically I found my problem revolved around remnants of norton/symantec trialware that I couldn't remove using uninstaller so download the tool from the Symantec web, when complete do the same with zonealarm firewall and restart with normal firewall in place.
It seems there are a number of small bugs especially regarding DHCP and routers, and NIC cards in Vista. It's a case of step by frustrating step until you get there.