Dump your temp files and cookies, try again:
For IE:
-click tools, click internet options
-click delete cookies, click ok
-click delete files, place a check where it says delete all offline content, click ok
-click ok
-close and reopen your browser.....you'll have to log into sites again
For FF:
-click tools, click options
-click the privacy menu
-basically click each entry, then click clear
-for cookies, make sure it is set to allow cookies