When you copy the clip art it will have extra symbols and numbers in them that you have to take out. I hope this makes sense. I'm not the most technical person so maybe I'm not explaining this right but I know when I started my cheat free clippie over, I had to take out the extra symbols that didn't belong, below is an example:
how a signature clipart looks from the clipart thread:
[img]http://www.disboards.com/wish/memberwish.gif[/img]
how it should look to get it to post in your signature:
{img]http://www.disboards.com/wish/memberwish.gif[/img}
Just take out the {} I put at the beginning and end of the string and add brackets instead like this: [ ]. Try making these modifications and see if it works. I hope this helps!