DBCC CHECKDB FAILED On SQL2k5x64 Activepassive Cluster

When using an activepassive sqlserver 2005 cluster (standard edition) on MS Server 2003 R2 Enterprise x64 with SP2 and I run the DBCC CHECKDB commands on any of the system databases I receive this error:



Check Database Integrity (selio)
Check Database integrity on Target server connection
Databases: All system databases
Include indexes
Task start: 2007-06-06T16:50:38.
Task end: 2007-06-06T16:50:38.
Failed-1073548784) Executing the query "DBCC CHECKDB WITH NO_INFOMSGS
" failed with the following error: "The database could not be exclusively locked to perform the operation.
Check statement aborted. The database could not be checked as a database snapshot could not be created and the database or table could not be locked. See Books Online for details of when this behavior is expected and what workarounds exist. Also see previous errors for more details.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.

Command:USE [master]
GO
DBCC CHECKDB WITH NO_INFOMSGS
GO
USE [model]
GO
DBCC CHECKDB WITH NO_INFOMSGS
GO
USE [msdb]
GO
DBCC CHECKDB WITH NO_INFOMSGS

I don't receive this error when I run CHECKDB on the system databases on our test environment x64 box (same OS and hardware).