RJ45 for 2 then add Wireless for Broadband?

I've a problem that given my next to nil network experience I can't resolve.

I had 2 computers (A + B both XP) linked on a home network using cable + 2
network cards sharing a 56k modem for the net. Worked fine all round.
Recently got Broadband with my neighbours and connected to it via a new
wireless network card to the DSL modem/router.
The DSL works fine but:

Computer A (with the wireless connection) can no longer see B in the
workgroup
Computer A cannot see any other the other computers sharing the wireless DSL
router/modem
Computer B Sees A but is denied access to it. Tried to run a multiplayer
game to confirm - didn't work claiming lack of TCP/IP.
If I bridge the wireless and cableLAN connections the DSL connection fails
(though I still maintain good signal indications)
Just tried to bridge now (having tried other things) and it does not allow
me to bridge 2 connections that are sharing internet connections even though
neither connection has ICS enabled.

How do I connect both computers and have wireless DSL (preferably on both)?
As bonus should I be able to see the other wireless computers? in the same
workgroup?

Any help greatly appreciated.

Stu