Some Advice Please
 

First, some background.

I've got two WinXP machines running on a local domain with a Win2003 server as the DC. I have the three machines connected to the internet via wireless to the wireless AP, up until recently this arrangement worked fine with the wireless connections sitting on their own and the wired connections sitting on network bridges, this doesn't work now. I can't have both connections active on the two XP machines because either the connection to the internet or the connection to the domain wil fail.

any suggestions?

So you've got Internet <-> Wireless AP <--- wireless ---> 3 computers?

Or are some machines hardwired into the access point?

no, for domain purposes the three are primarily linked by ethernet through a linksys router, all of this is upstairs, all three also access the internet via the wireless ap which is downstairs

So they've all got two network interfaces - a wired NIC going to the domain, and a wireless NIC going to the internet? Why not just attach the internet connection to the wired network and cut down on complexity?

because the internet connection is downstairs and the machines are all upstairs, hence the wireless

So then do all of the machines have wireless network cards, or just the domain controller?

they all have wireless, although i have played around with letting the other two access the internet via the dc's 'net connection but it's never been stable enough