Yes, there are.
My site looks perfect in IE 7, but when I upgraded to IE 8 this morning, one of my pages backgournd images does not display and the alignment of text in the top nav, footer, and left and right columns is screwed. Having said that, this is likely an IE issues rather than CSSS. When I click the Compatibility button in IE 8, my site looks cool again. This is a pain if your not a css coder.