I have asimilarenvironment to you and have seen the windows stuck in the loop before.
Remove theFCcable from theHBAand let the server boot. Make sure the cluster service is dependant onsnapdrive. This way thelunswill be available when the clustertriesto start. Reboot and it should work.
Hope this helps
Last week I did the upgrade fromSME3.2 to SME5 and all thedependencies. No issues to report other than when upgradingMPIOthe DOS box which opened gets "stuck" on upgrading plug and play devices for about 10 minutes then completes.