Whats the channel width set to, you could try changing that to 20/40, or just 20 depending on what default is. I'm not going to default mine out right now just to check.
Also, if you're only connecting B/G clients lock down the radio to B/G only, or even G only depending on what you are connecting.
you mentioned wired as well....
Do you have MAC filtering running on your router? Static IPs set on your laptop?
Maybe call Gateway.....Sounds like your routers working. You may be statically set to the linksys router you mentioned worked. Check the IP config, make sure you're set to Obtain Automatically.