A little more details would be helpful. 1. What OS do you have and what browser are you usinge?
If you are using Windows & internet explorer are you having issues with other sites? IF the answer is yes clear all browsing history -Control Panel - Internet options - general - browsing history - delete
If this does not help try a differerent computer or install a differnet browser such as Fire Fox http://www.mozilla.org/en-US/firefox/new/