[CentOS] firefox problem with redirects on centos 5

I'm having a peculiar problem with Firefox only on my Centos 5 desktop. Every time I try a link from a search engine and even when I type in a location, I get a redirect error:

"The page isn't redirecting properly.
"Firefox has detected that the server is redirecting the request for this address in a way that will never complete."

However, any link in my bookmarks works, as do a couple of remote IPs I have in /etc/hosts.  (Does places.sqlite store IP numbers? )

All the machines use the router for DNS,  and the router goes to OpenDNS.

This problem *only* affects Firefox, and only on the one Centos 5 machine. I have Centos 6 machines, Macs and Androids on the LAN.. Firefox works fine everywhere else. On the Centos 5 box, Opera works fine. 

 Any suggestions?