Lost all my subcategories in the BO Need Help :)

[Dickie]

This problem only started yesterday and I have no idea what is going on whether I have edited/deleted a file on my site or maybe its to do with my hosting company :S.

The problem is when I go to the catalog tab none of the subcategories of mine are showing, but sometimes they are!

I have attached pictures of both times when I have the categories and when they are gone.

Also I have noticed that when the categories have disappeared if a customer tries to add a product to their cart they are unable to view anything in the summary just a total-less cart and if they try to checkout and pay it creates a free order in the back office with no product in the order form. (also attached a screen shot of that)

But this problem comes and goes if you look at the order screen shot we have had a free order when the categories were gone but then we had a couple of normal orders after that so it is very strange?

Please help if you can.

Cheers