Well I just tested this on my 37000L with .91f3+ and kill logo. It dances circles around navi and allows boots of backups while the HDD is live. Naturally with no disc in the drive and the chip live BB Navi boots fine (you DO NOT want to do this if your ps2 has net access). Thanks a ton guys, I never liked my "hdd disable switch" and the idea of how much stress it was putting on the unit.