Can't delete partially downloaded files from Firefox

Hi, I need a bit of help, and I haven't been able to find anyone else having the same issue.

I was downloading a whole heap of .jpg files in firefox, and two of them didn't get completed. One says the file extension is .jpg, the other .part. Neither of them will open, I can't view Get Info, I can't rename them, and when I try to move them to the trash, I get told that they can't be deleted. I didn't realise that they hadn't been completed, and have deleted them from firefox's download manager, so I can't restart the download. Now they're just sitting on my desktop, and I can't do anything with them.

I'm using Mac OS 10.7 as well, which I'm discovering is buggy! So any advice on this issue would be much appreciated!

Ok, sorry, I managed to fix the problem. I had stuff downloading, and once it was finished, I did a restart and the files vanished. Its amazing how often that works