Ok, left unit powered up overnight as a test (I usually turn off when not in use). It apparently does go to a power-management mode as well as have an internal fan. Could not hear it running at all, but could feel it running (maybe fan?) by touching the unit--which was very cool to touch.
Here is what happened as part of my test. When I went to manage device, got the need to activate pop-up. I clicked OK. Then went to manage device again. This second time it responded immediately. So, no real issue. Either turn it off when not in use (and get the two off/on pop-ups) or leave it powered up and get a single activate pop-up.
Very pleased with the LaCie 500GB. May buy another for our second 622.
I noticed that too, very cool to the touch- and I leave it on 24/7. If there is a fan in there, it is dead quiet. I could feel a very faint draft out of it. I love this drive.