Edit Button Not Working

[PH03N1X]

This affects all skins on my forum.

Whenever I click the "Edit" button to any post, in any thread, in any forum, it will freeze and not go into the edit mode inside the post.
However, if I right click and "Get Link Location" and paste in the browser, I'll be able to.

I run PHP 5.2.4 if that makes any difference
Please help.

EDIT: I installed the mood manager and the same is happening to that. It won't go past "Updating mood". I think it's a problem to do with Ajax.

Thanks,
- Mike