Help Catagories no go WP 2.5 upgrade

Ok … I upgraded from 2.33 to to 2.5 tonight without issue. Front page looks great and shows my posts, the pages work, and the admin panel works without hitch, but when I select the catagory, I get a post not found error. I pulled the catagory bar in control panel and restarted it just to see what would happen, but it didn’t work either. Not sure what’s going. Thanks in advance for the help.