I've found a problem but I'm not sure in which forum to post, or indeed what it might relate to....

This product doesnt seem to work

Similarly this category doesnt work.

The error message I get from my server is " Zero Sized Reply ". When I try from home it just says "page cannot be displayed".

All other categories and products seem to be fine. For example this

I can view and edit this category and this product in catalog admin.

Im running 1.3.0.1 with PHP 4.4.3

The only thing I can think of that may have caused this is that I installed user tracking recently(although this seems to work fine).

Can anyone shed any light on this? Many thanks.