Help! My site is being redirected to a nonexistent page!

My site is being redirected to a blank “about” page. For example: http://www.mywebsite.com/about instead of http://www.mywebsite.com. This happened after I updated my pages. I’ve since checked the code in the nav.php file, and permalinks but it all looks fine. My website is now just showing “page not found” because of the redirect to the blank about page. What should I be looking for? Any suggestions to fix this and stop the redirect?
FYI: wordpress is saying that the installation of the update to version 3.0 failed and yet my dashboard says I’m running 3.0. Related?
Thanks in advance for the help!
Rachel