Got this from McAfee today:
MSFT released a hotfix to address this issue. The Hotfix can be downloaded here:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;2674551 (Redirected mode is enabled unexpectedly in a Cluster Shared Volume when you are running a third-party application in a Windows Server 2008 R2-based cluster)
Not tested it yet myself, but would be interested to hear how others get on.