On Apr 22, 1:48 pm, Mike Spurgeon <m...@spurgeon.net> wrote: > schmidtd wrote: > > What on earth might be causing this? > > The drive? Sorry, forgot to mention that too. I tried different Disk ]['s in the same computer, all exhibited the same behavior. Put those Disk ]['s back on a working Apple, and they work fine. It really seems to be tied to this particular motherboard.