[MT-AU Public] SXT Kernel failures and reboots

Hi All, I have posted before about RBSXT reboots for no reason but nobody else seems to be having the issues. We found that upgrading to 3.41 firmware seemed to stabilise them for some time, but in the last couple of weeks they just started rebooting again for no reason, sometimes every 4 or 5 days even. Has anybody else come across this issue ? Netinstall isn't really a viable issue for the majority of them as they are of course up on masts and in production, I am looking for some way of trying to stabilise them if possible. They are currently running 6.40.8 or 6.40.9 and 3.41 firmware. Any thoughts would be appreciated apart from replacing them. Regards Paul