Yep. That's why the drive is bizarrely locked permanently. It seems you can't do a lock, unlock cycle too many times before it decides to freeze permanently. I've looked at the security flags set and it doesn't even think the drive is locked. HPA is on but doesn't seem to affect it.

Have they made any further progress on working out what's wrong with them? I've not tried the qunlock utility since the drive got locked so I've no idea if it's changed.