I heard that they weren't working, but not due to kernel panics.
What seems to happen is most programs check to make sure you have enough video memory to run them (or maybe the OS does).
When you have a card with 2GB+ of memory, the card returns a NEGATIVE amount of video memory (bug, whatever) when it's queried for its video ram value. Many many programs will then say you don't have enough video memory to run them, even though you do.