Unload of zaptel causes hardware lock

Hi all!

we are running asterisk on a FC4 64 bit (2.6.11 kernel version).
When we try to unload zaptel from the command line, the server hangs up and a hardware reset is needed.

Just before hanging, in the messages log, we can see “Badness in local_bh_enable at kernel/softirq.c:140 (Not tainted)” and other information about instructions.

Any experiences on it?