asterisk users - Aug 2005 - Sirrix bri card:killing the machine

Hi all,

I have a sirrix bri card, connected to 2 ISDN lines.I used to get a lot 
of slips on it, so i put the 'master' setting to 'yes'. But
every couple
of hours the machine completly hangs, and i have to reboot it. I only 
get 1 or 2 slips,I dont know whats wrong?

yusuf