You should be able to do it to your own images, but you need to follow what is known as 'The Way Of The Badger Nose' (You don't know how close you were!).

Let me enlighten folks ...

When you have logged in click on your name at the bottom of the page. This takes you to your weblog/profile page. Click on the image count in the bar near the top and this will list your images. Next to them you should see Edit|Delete by the side of them.

Hope this helps.