Last days, I was developing a pure Ajax JS component from scratch that should work cross browsers, I really found nightmares during my way because of the ugly bad stupid IE.
One of the bad IE stupid features that really suck is the IE Ajax Caching.
UnLike FF, If you are trying to send simple Ajax GET requests to your server servlet, you will find the stupid IE returns stale old request data.
After spending one hour in investigation, I found the way that got me out of this hole.
To solve this problem you should add a random dummy parameter to your GET url request to force IE to refresh itself.
var url = "/RichTextEditorWorld/ImageUploaderServlet?ieDummyStupidParameter=" + new Date().getTime();