I use ant video downloader, though I don't D'L much porn.

Edit:

Well, I did use it up until earlier today when all that would happen when trying to DL a clip, was the blue 'down' arrow that shows the progress of any download would just keep 'flashing' and when I clicked on it to see the 'progress', it would just mention 'chunks' of 0kb.

So I've un-installed it and told them what happened.