Hang after running out of memory

I have been following the thread here on current_at_ about problems occuring
when running out of memory, so I wrote a C++ program that simply mallocs
about 144M of memory. My system has 256MB+491MB(swap). I can run the system
out of memory just fine by running multiple copies of the program, and the
kernel does kill one if I run too many, however shortly after, when I go to
killall the programs the system hangs, (although pings, etc manage to
survive for a few mintues longer) and I have no choice but to press the
reset button. While it is hung, I _can_ press ^T and it shows the load,
which increases by 1 about every 45 seconds:

load: 11.58  cmd: killall 20125 [running] 0.00u 0.00s 11% 292k
load: 12.27  cmd: killall 20125 [running] 0.00u 0.00s 12% 292k

Also, the console is just as unusable as any other terminal. I'm not sure
what is going on, but this is reproducible, and I can post more info upon
request.

-Craig