Just want to outline a few tips for troubleshooting issues you may have with the site that may resolve the problem.
First Try logging out of the website by clicking on the Log Out button in the upper right corner. Close the current window you have open, open a new one and connect back to the site. Click logon and put in your username and password. Try attempting to do what you where doing before.
If that fails try clearing your IE cache. You can find instructions here
Internet Explorer 6: How and Why to Clear Your Cache . You may also want to upgrade to IE 7.0 you can do that by going here
Internet Explorer 7: Home IE 7 is a little more friendly an adds Webrowsing. Close all IE windows go back to the site and try again.
Have someone else try on loggin in or create another account to try or If that fails and you have another computer try loggin on to that one and seeing if you are able to perform the action you where trying. If so then it is not a problem with your account, but one with you profile or computer.
If none of the above helps PM one of the Admins and they can try and assist you.