linksys wrt110 issues as second router

I have a linksys wrt110 connected to a befser41 wired router as a secondary router. Dhcp turned off etc. I have had this set up for over a year and in the las week all my computers started running very slow internet. I disconnected the wireless router and everything ran fine again. I reset th wrt110 and upgraded firmware then plugged it back into wired router, again system starts running slow. Any ideas or is my router going bad?

 

Never mind, it turns out the Bef wired router was going bad.