largish lock icon showing on the Karma screen, and requiring a power cycle to clear?

Djc, are they using the latest firmware (1.41)?

I can't imagine you being able to power down the player if the lock is engaged unless there's something screwy with the firmware. When my lock is engaged, I can't power off my player at all.

Since you're reporting this second-hand, perhaps the chain of events was somehow misreported. Maybe they just used the lock switch and didn't know it. Or perhaps the lock switch is partially engaged making it intermittent. Or, as was already said, it could be a faulty lock switch.

I looked through the online user's guide, and saw no mention of a lock icon.

I performed a search on "lock" in the manual and found several references to the lock switch. Although no mention of the on screen icon.