If you specify a list-style image for the default list (UL), IE applies that to all lists - even when they have an explicit list-style of "none"!
The way to get around it? For your lists that you want to NOT display an image, give them
list-style:url('none') none;
Which seems to work.
I really hate IE. My favorite bug is still the inheritance of position styles by some elements. Crazy that be.