CentOS - Dec 2005 - CENTOS3.6: taskset crash

Hello

I am using memtester V4.0.5 on x86_64 arch (4x PROC-4GB total) and it
works fine.
When I want to launch it on only one CPU with the taskset cmd the
machine
crashes.
here is the cmd i am using
taskset 0x00000002 ./memester 1000 
known issue ?
Thanks
Jean-Pierre