I hope somebody can help me out...

I started building a website and after the cosmetic adjustments (and adding language package, image handler and easypopulate and moving the site one folder up) I decided to delete all test-products and add a few new ones with easypopulate.

For some reason (don't know why) this has gone wrong: the products show on the site as they should, but they are not present in the admin - catalog so I cannot reach them for editting or anything else.
I can buy them to get rid of the products, but then the categories of course will stay.

My questions are the following:
what can I do to remove the categories? They are not present via admin - catalog - categories/products. Is there another way?

And does somebody have any idea what can be wrong? The txt file I used for uploading looks good...