I wouldn't stick my hands into fire for this, but it could be the BIOS
of the MoBo that's faulty, and maybe a flash is required. Other than
that, I find it very strange that the kernel won't pick up the other
processor.
One thing that does suck is that I can't make the SMP version of the 2.6
kernel play with my dual-processor motherboard; I think, though, that this is
a problem with the 2.6 kernel and my motherboard, not with FC3, since I had
the same problem with SuSE.