I have two SATA drives in a JBOD enclosure connected to an eSATA PCI card in my e2008 Mac Pro running Lion. I can eject either or both of these external drives fine, but if I power off the JBOD enclosure while the Mac Pro is still on, the Mac Pro squeals super loud like a smoke alarm. It's a sound I didn't even know a Mac could make -- a loud, piercing shriek. Any clues as to what the sound is? I suppose it could be the eSATA PCI card making the sound... but it seems odd that a tiny PCI card would have the ability to generate a sound.