I have for quite some time now been unable to get my MBP to sleep by itself. Not having the time to look into this for a while, I finally today got around to have a looksie at my system. Running fs_usage displays that there are three processes that are constantly pulling the system, and Parallels is one of them (the other two are httpd and mysqld, but I don't think any of these are to blame since I have had them running for ages on my Powerbook without any such effect). However, /Library/Parallels/.dhcp.en2 is constantly stat'ing the filesystem, and my guess is that this keeps the MBP from sleeping (since there is vital diskactivity going on). Anyone else with this problem able to confirm or deny my suspicions? -e
I'm not using host only networking, so I just kill the Parallels DHCP server when I boot the Mac since it uses resources, and my guest networks just fine. I'd love an option in the Parallels interface to disable it.