2 routers, one network problem

[Jesusfrk611]

I have a Linksys wireless router hooked up to the internet connection, and was given a Linksys wired router and wanted to use it as a switch to get more ports instead of using my 10mbps hub... I know you have to go through trouble to get the second one working. Well, I looked up how to get the second one working as a switch. I disabled DHCP and it worked fine for wired. So I left it alone. The next morning I get on my notebook which runs off wireless and it wasn't connecting well. Sometimes I'd get it to work for awhile, then it would go off again. I disconnected the second router and all was well with wireless...

How can I get this thing to work without disrupting the wireless?