Crash on WAN switching

[gobris]

Hello
I configured as load balancer  between two pppoe interfaces..
WHile two interfaces up it works.
But if i unplug or disable one of the interfaces.. after a few seconds....
lots of lines start on console window then server restarts...

I sent the error report that popped up on the webgui after the reboot..

Just wonder if anybody has such problem or it may be a hardware failure (faulty ram etc) on my side..