PS3 Auto Logoff is unsafe

[Ebojager]

I was waiting on my party to figure out what they were doing so left my character sitting while I ran across the street to the store, probably was about 30 minutes or a little longer. I come back my screen is on, the sound is on but my controller seems asleep. I push to wake it up and it just blinks and shuts off. Keyboard is unresponsive but the lights are on. I had to hold the power button down to force a shut down.
I have the older fat PS3 maybe 2nd edition the 40gb version with updated 250gb HD. Plenty of space left. I had a USB keyboard plugged in as well as the controller plugged in via USB. I had spoke to another ps3 user and his did not lockup. He also had a 2nd generation ps3. Not sure if maybe its the USB keyboard and controller or what, but I don't want too be testing it out if its gonna lock up.