I was trying out Prism – by Mozilla.  Neat stuff.
It enables you to convert web apps into desktop apps. Its pretty handy in case you are using GMAIL (esp when GMAIL offline support will start).

Anyways, I ended up getting a corrupt session for GMAIL and was getting the following error:
“Redirection limit for this URL exceeded. Unable to load the requested page. This may be caused by cookies that are blocked”.

In XP, go to Document Settings and which ever user you are using. Go to Application DataPrismGmailProfiles.
Here you will see a folder with a weird name; open the folder. The ciminal cookie file is “cookies.sqlite”. DELETE THIS. Open up the gmail desktop application again, and it’ll start working.
Hope this helps : )