Duncan Epping recently blogged about an issue with Storage vMotion and vDS causing HA restart to fail, while svMotion is in progress. In order to fix the issue, William Lam and Alan Renouf have both written scripts to mitigate the risk. The scripts and the ways to fix them can be found at
http://www.virtuallyghetto.com/2012/04/identifying-virtual-machines-affected.html by William Lam and http://www.virtu-al.net/2012/04/17/identifying-and-fixing-vms-affected-by-svmotion-vds-issue/ by Alan Renouf.
In no way shape or form do I take the credit for this solution. This blog is a personal reminder to me of weird issues that I have come across. If this offends any of the original authors, please let me know and i will pull it down.