They have the option to use the 2.2.17 kernel, or the 2.4.3(I think that is it) kernel. I use the newer kernel because I don't need the old compatibility junk. But the old kernel is there for people with older machines who have hardware issues with the new kernels.
P.S. Progeny kicks major ass, I just wish I could get the whole CD issue worked out. GRRR