mprime error with dual AMD64 Linux

Hey there,

I am trying to get mprime running on a dual core AMD64 Linux (64bit) system.
The torture test (mrpime -t) seems to work fine, but as soon as I start
accessing my disk in a second processes (e.g. doing something like ls -lar)
I get the 'ILLEGAL SUMOUT' error in the mprime processes.
The disk is an array of five disks operated by a Raidcore (Broadcom BC4000)
controller. (The kernel module is bcraid.ko, kernel is 2.6.x. I tried several versions of x ).

Has anybody a similar configuration and/or experienced this kind of
behaviour ?

ANY help is appreciated.

Happy Hacking