sysrq-c oops results in hang, not reboot. panic_on_oops=1.

Hi all, I do a sysrq-c in order to force an oops crash. It works (as it always has), and dumps the stack. However, it hangs indefinitely, no longer rebooting. kernel.panic_on_oops=1, and kernel.panic=0. Is there anything else which determines the behaviour at this point? Thank you, in advance, for any insights, ali PS I _have_ gotten this stuff (incl. kdump) to work before. PPS I'd run into this before, a while ago, but did not tend to it till now, when I _have to_! :-) I'm getting a very reproducible crash (of 2.6.39-rc3 code which I have not touched), and would like to get an idea of the cause. Mind you, that just hangs the box, so the above will not be of direct help.