Random reboots sounds like a possible hardware problem to me. Have you had any sudden reboots unrelated to these two apps?

Just for the record I have never had either of my N9's reboot by themselves while running at stock clock frequency. (Not counting single reboots done by some install script)

Might be worth to run memtest and see if your phone reboots/crashes doing it.

[EDIT] Here's link to the thread where you'll find it: http://talk.maemo.org/showthread.php?t=89076