Vista can see network but wont connect

Hello,

have a strange problem with Vista when trying to connect to a wireless network. To start with it worked fine, then suddenly it disconnected after a couple of hours use. When I try to reconnect it says it can't as there is no response from the router.

I've tried connecting via my laptop and that works find (it's an XP laptop).

Last night I installed the latest vista driers and it worked again. Then this morning, the same problem. Reinstalling the latest vista drivers now has no effect.

I've tried connecting manually, no difference.

I've also tried adding the DhcpConnForceBroadbastFlad and setting to 1 in the registry as sugegsted on microsoft website, but again no difference.

Does anyone have any ideas?
Thanks