Categories Not Displaying - Wood, Trees Etc.

[UncleSteve]

I'm having trouble seeing the wood for the trees at the moment, plus I'm so tired, so a little help will be welcome please.

 

I have SEO URL's installed.

 

My index page displays fine, as do the list of categories on the left column, however if I click on any category, the page loads the left column, but nothing else, so there seems to be a problem with the page it needs to upload.

 

The url in the address bar looks correct ( mydomain. com/ store/accessories-gen-c-29.html)

 

Give me a clue where to look please, as I've been on this so long I'm having problems thinking straight.

 

Thanks