I have exprienced multiple times now that after an unexpected shutdown of a Windows 2008 R2 Standard guest running on Hyper-V 2008 R2 non SP1,
the CITRIX licensing server service will not start or stay started after manual intervention. In all instances, uninsalling the licensing server and reinstalling fixed the issue.
I did not have to restart my server after removal of the software or reimport my license files. Just remove and reinstall.
See the below CITRIX article which references the known issue for Windows 2003 but does not reference Windows 2008.
You can also follow a thread on the forums to get more detail around what other users are experiencing.
If anyone reads this and can verify that build 10009 will also resolve the issue for server 2008 please let me know. Of course the real ix for me is to determine what is causing the cluser service to crash unexpectedly on one of my cluster nodes!