Go Advanced Button not working

[Digital Jedi]

One way is to have a look at the source code when it does err, and see if anything looks amis. Run the source code through the W3C Validator if nothing jumps out at you. But first go to General Settings in your vBulletin Options and turn on Add Template Name in HTML Comments. This, while not always the quickest method, is one of the first things I do when I encounter something like this.

If you're not familiar with validation, there's an article in my profile that you might find useful.