SQL problem? In back office Catalog Not showing

[Orhion.ro]

I have a little problem:
I imported new products and categories but after that, in BO at Catalog it only shows 2 categories and i cannot delete anything.
Is there a way to regenerate the SQL at the time after the instalation of prestashop? it would be much easyer for me to start over than to fix the problem

Here you have a printscreen:
http://www.orhion.ro/printscreen.JPG

You can see that even that i am in the bottom of the page there are only 2 categories and no products

[wildchief]

to be honest every time i screw up in development i back up my changes - if you can remember them and reinstall the whole lot