Question : Exchange 2003 Cluster Errors

I'm getting the following errors on the active node of an Exchange 2003 cluster.  It happens once a day and has been happening for a few days now.  Can anyone give me an idea of what is going on?  We are not experiencing any issues, but would like to know if there is something imminent we need to anticipate.  

Event Type:      Error
Event Source:      MSExchangeCluster
Event Category:      Services
Event ID:      1005
Date:            2/28/2008
Time:            10:01:44 AM
User:            N/A
Computer:      
Description:
SMTP Virtual Server Instance 1 (XXX-EXV01): The IsAlive check for this resource failed.

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Data:
0000: 4c 27 00 00               L'..    

Event Type:      Error
Event Source:      MSExchangeCluster
Event Category:      Services
Event ID:      1005
Date:            2/28/2008
Time:            10:01:38 AM
User:            N/A
Computer:      
Description:
Exchange HTTP Virtual Server Instance 100 (XXX-EXV01): The IsAlive check for this resource failed.

For more information, click http://www.microsoft.com/contentredirect.asp.
Data:
0000: 4c 27 00 00               L'..    

Event Type:      Error
Event Source:      ClusSvc
Event Category:      Failover Mgr
Event ID:      1069
Date:            2/28/2008
Time:            10:01:44 AM
User:            N/A
Computer:      
Description:
Cluster resource 'SMTP Virtual Server Instance 1 (XXX-EXV01)' in Resource Group 'XXX-EXV01 Group' failed.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Event Type:      Error
Event Source:      ClusSvc
Event Category:      Failover Mgr
Event ID:      1069
Date:            2/28/2008
Time:            10:01:38 AM
User:            N/A
Computer:      
Description:
Cluster resource 'Exchange HTTP Virtual Server Instance 100 (XXX-EXV01)' in Resource Group 'XXX-EXV01 Group' failed.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Answer : Exchange 2003 Cluster Errors

Is it happened at the same time every day?
It could be some processes that stop or monopolize SMTP at the time EXRES checking