Is there any known issues with partial config go missing from a functional ros?
I run my ros from a usb dongle if that could be the issue ?

Ive had this happen to me a few times on differnet machines
I first thought it was the v6 beta but i have a tottaly different machine now on version 5.22 x86
on a tottally different usb dongle.

other issues i just noticed was some of my kvm's some times hang and become unresponsive, some times i have to delete the img
to get it working again

I've seen the config loss on Routerboard devices. One lost config for no apparent reason, the other one had some water in it what shorted something.

So i loaded all my kvm images to a sata drive, and now its just ros that runs on the usb dongle...

I think that the usb dongles cant handle alot of read/writes that's my suspicion