Both those indicated 3.2, which surprised me slightly.
However, I remember that part of the NVidia kernel module is closed source (compiled) with an open source wrapper, so I was wondering if perhaps the closed source bit was gcc 2.9x compiled.
However, I tried again tonight with the newer kernel src rpm (3123) and had no problems at all. Before I had 2960, and I wonder if that was the cause, as I can't think of anything else..
Thanks for your suggestions though - much appreciated