Your problem cannot be addressed without the following.
What is the model of the replacement 2Wire?
The newer ones are crap in my opinion.
I have an old 1000HG and it functions flawlessly.
Recently the power supply dies and ATT had to ship me a replacement.
They sent me a 2700hg-b and the first thing I noted was that if it senses heavy traffic (for example during torrent downloads) a "hit" will come from ATT's DHCP server and it will go up and down like a $2.00 whore, renewing it's lease all day.
The reason behind this of course is to discourage inexperienced users from P2P file sharing.
That said my 2700hg-b maintains a pretty solid wireless signal.
My only question for you is this;
Can your linksys wrt54g utilize WAP?http://en.wikipedia.org/wiki/WRT54G
If so disable wireless in your 2Wire 2700hg-b.
If the setup is standard, 192.168.1.1/24 (192.168.1.1 mask 255.255.255.0) network that come plug inplay on 2Wire just open your browser and go to 192.168.1.254 and enter your password to log into the router.
I know you probably already know that. But I start from scratch.
Click> Home Network.
Click the disable button next to wireless.
Then set up your WRT54G as it were receiving it's IP instructions from a DHCP server (as if it was answering to an ISP)
Consult the user guide.
I have been looking for the UG for your wrt54gs the problem is that Cisco is making Linksys docs hard to find these days. Got to push the Cisco ASA series you know.
Best I can do is: http://forums.linksysbycisco.com/linksys/b...message.id=3153
and wish you luck.
However from a networking stand point the most un-complicated thing to do is disable wireless on the 2Wire and let it handle the ISP auth processes and DHCP services only.
Then set up your dependable wireless access point (the linksys) to get it's info from the 2wire.
If you send me the models (and PDF manual for your linksys) I wil give you precise instructions that will work.
I hope this gives you a starting point.