KERNEL_PANIC null memory on KM_SLEEP request

[Jose Morales-Wade <josemorales-wade@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

I have a Dell 2650 with 4 Drawers of disks connected using two Perc 4DC 
raid cards.
I'm running 2.4.20-19.9.XFS1.3.0smp. The server has two cpu's and 2GB of 
memory.
Yesterday the server kernel panic with a :

KERNEL_PANIC null memory on KM_SLEEP request

The memory usage for the machine looks "normal" around the time the system 
crashed.
There was hardly any swap going on.

Any ideas?