There's been a *lot* of concern about those drives, in that they spin-down automatically *much* too frequently, leading many people to expect premature deaths.
Thanks for the heads up, I will install smartmontools and get it reporting every so often. The home server is only really alive when I'm at home so only really a couple of hours a day at the most, so maybe this behavior is ok for me? They are in RAID and have a 3yr warranty, so I'm not going to return them in a panic... but we'll see how it goes. If/when either of them fail I'll post back here!
I wish my damn SATA-CF adapter worked properly so I could install the OS on there.