I think it is pretty much confirmed that the reboot-bug can corrupt the file system. Also, after 17 random reboots in a row, the N900 is a brick and needs reflashing.

However, the myth that reflashing will solve random reboots is pretty much busted, at least untill a new FW is available. There are some rumors that Flashing with UK FW will somehow solve rebooting issues, but as of now this is a rumor, and I doubt it will fix anything.