It happens alot over at the JA forum, there have been a lot of complaints about it by people there. I don't know if it's due to security software, or the browser, etc. I have IE 7, and use AVG PRO, and haven't had this happen at all, guess I'm just lucky. One suggestion would be to try firefox, or modzilla, but first I would do a disk cleanup thru system tools, maybe even try that first. It maybe a windows based issue, but on the server's side verses end user side.
Maybe a posting in the main forum will get some help from a computer guru that may know the answer.
Dave