IE Problems

Hey, i seem to be having some trouble with getting setInterval() to work in IE.
Basically whats wrong with it right now, is that its not looping my ajax function at the moment. It works fine in firefox, could this be a caching issue?
Or does anyone know of a solution.
You cant really see that its not working, but when you press delete on an image, it stays in the list, but it actually does get deleted.

http://imgyard.net - Right click for source code

Any help would be greatly appreciated.

Edit: I think setInterval is working, i'm now thinking its definitely a cache issue.