Since my Beta 2 was acting very flakey I decided to format the partition and try a newer version. It installed cleanly and came up with no problems. One issue I discovered is that avast! antivirus (free for home use) does not work on build 5536. After installing and rebooting, you'll get a message that Windows Vista has disabled a faulty driver. Hunting around on avast!'s forums I found out that someone claims MS made a mistake in "banning" avast!'s driver and it would be corrected for the RC1 release coming soon.