Not sure whats happened here.
For some reason out of the blue, my gallery has stopped working.
When you go to view it:
The header loads up, and then repeats and repeats and repeats etc
So you end up with a continious header, one on top of each other.
I deleted the header.htm in case it got corrupt or something, but that wasn't the cause, the page just continues on loading and loading.
If you view the page source, you'll see that just keeps on loading, and then repeating itself time and time again.