Pauline, you don't have to reupload your files to recatagorise them. There's an "Edit" link in your portfolio that you can click on and just change the catagories when the new catagories get implemented. It won't require a re-upload.

Just click the "My Account" link above and next to each of your entries you'll see a link for View and a link for edit. Click edit and then just change catagories there.. 

It is a miracle that curiosity survives formal education. - Albert Einstein