Help with some really strange problems

I'm coding the javascript for a portfolio, and I'm coming up with some really strange problems.

http://seekond.com/reDesigned%20Files/

Try clicking some links. At first, it'll fade out/in normally. Eventually you'll come across a page where you'll get stuck in the fadeout-loading mode.

The overlay is set to fade out when the ajax request is complete. Unfortunately, in some cases, the ajax request completes....but the overlay doesn't fade out!

I know this because if it goes into an infinite loading sequence, you can type javascript:fadeout();void(0); in the address bar and it'll show the new page.

I'm using JQuery for the ajax request. Could that be the problem?

Thanks in advance for any help.