Have you cleared the cache, temp. files, and cookies from your browsers? How about the temp. files from your system?
As you suggestion, you can run ATF Cleaner by Atribune:
http://www.atribune.org/index.php?option=com_content&task=view&id=25&Itemid=25
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It is a small file (50KB). Run it > Select All > Empty Selected. This is for the first tab only.