SMP kernel 2.4.5 reboots spontaneously

Hi,

My machine has an
- Intel D440LX motherboard (440LX chipset, onboard Adaptec AIC7880U SCSI, onboard EEPRO-100 NIC, onboard Cirrus VGA),
- 2 Pentium-II, 266 MHz CPUs
- second EEPRO-100 NIC
- SCSI HD and CDROM

Using the 2.4.2-smp kernel from RedHat 7.1 gives spontaneous reboots, the 2.4.5 kernel too, when configured for SMP.
No crash dump available - applying the lkcd patch didn't help either. The machine runs stable with a uni-processor kernel (2.4.2), though.

Does anyone have any idea what's going wrong here? Reactions please also cc: to my email address.

Greetings,
Daniel Tuijnman