I observe an OpenRG reboot exactly every 2 weeks. Home Hub 4, ADSL. It is unrelated to line drops, since the log clearly states the OpenRG is triggering the reboot before the line drop (someone else posted logs here proving this).
Screenshot of HH4 log when reboot is triggered.
(The firmware version is unchanged from what it was before the reboot, so it's definitely not a firmware upgrade).
What can I say, I'm better at remembering numbers than judging the amount of time that's passed. 🙂