Wondering if anyone else has seen an issue like this. My iMac is working fine since the Lion upgrade while I'm actively using it. However, I've noticed when it goes to sleep mode, my time machine external disk is spinning up and down constantly. It drove me nuts and I finally had to eject and power down the drive to stop it. I haven't seen other reports of this, but I would imagine if it's a bug, someone else has to have run across it.