Problem erasing temporaty internet files/history!!!

Everytime I try to erase my TIF/ History eraser turns them all into thumbnail size images, they are usually just a list of files/images in my TIF and history folder but eraser changer this ! :?

Once I erase the thumbnail size files, I go off the page. When I click back in the TIF folder the list of files is back to normal but all the files I thought I had deleted are still there! Similar happens with history.

All I do is go to the TIF folder, right-click and then click erase. It always looks like it's working but never really does.

If you can help me out please post! :)