Symantec has released an updated 3.5b1 beta version of the Speed Disk component of Norton Utilities. It is available at a special page on their web site. It primarily adds new features; no mention is made of any bug fixes. (Thanks, Brian Foster of Symantec.)
Update: When I tried this, it reported that my disk was damaged and so it could not optimize. It said I should run Norton Disk Doctor. However, when I checked the disk with NDD, it said the disk was fine. Another reader has also reported problems getting this Speed Disk to work.