[ic] Strange redirect behavior - only in Frefox

[DB]

Suddenly in the last day or two I'm seeing some odd behavior in both
catalogs running on my server. I've made no recent changes to the server
or to IC configuration.

If I click the link to the basket:

http://www.domain.com/ord/basket.html

Firefox 3.6.13 under XP shows an error:
"Firefox has detected that the server is redirecting the request for
this address in a way that will never complete."

Also if I log into the admin area, I get bounced to the admin login page
each time I click a link such as "content" or "tables"

I've rebooted my local machine and the server, and also cleared all
cookies and cache.

This seems to only happen in Firefox, not in IE or Chrome. Does anyone
recognize this behavior or have a suggestion about what may be wrong?

DB