process segfault messages on AMD64

Hi, On a CentOS 4.2 box (AMD64 3000/Socket 754). I was trying to run
Pound <http://www.apsis.ch/pound/index_html> ver 2.0b4.
Whenever I connect to Pound, it segfaults leaving these messages in
/var/log/messages

Dec 14 19:50:37 124 pound: MONITOR: worker exited on signal 11,
restarting...
Dec 14 19:51:01 124 kernel: pound[28106]: segfault at 00000000000000d0
rip 0000003feaeacd9f rsp 00000000400bc700 error 6

I will try to see if I can get gdb to help but my experiences with gdb
on multi-threaded apps haven't been so good. In any case, does anybody
know what 'error 6' mean from the kernel message ?

Regards, Yusuf