Little more information about the cluster. Windows 2003 R2 SP2 patches up to date. 2 node cluster. It is not running hyper-V.
If you read the whole thread it details that the issue affects any MS cluster using Cluster Shared Volumes.
Basically it drops the CSV into redirected access mode (I've never used MS clusters so i've no idea what that means ).
During the thread postings mention that the only temporary work around suggested by McAfee was to roll back to 8.8 (with no patch) which would suggest that excluding the drive is not enough to avoid this issue.
However right at the end a posting mentions that a recent hotfix from Microsoft has cured the issue for him.