> A kernel for another machine, using the fxp driver, works fine.

What I forgot to mention:

 - it's not a compiler optimization bug (I compiled without -O)
 - the other difference between the working and non-working machine
   is the CPU: the working one is a Pentium II, the non working is
   a 486
 - it's definitively no hardware problem, as rebooting with the old
   kernel still gives me a working machine

Martin