There are list of Troubleshooting Articles which may be worth Reading for Installation & Troubleshooting the Issues related Windows 2008 vista collector in SSIM.
Troubleshooting for Windows 2008 R2 Event collection using Windows Vista Event Collector. :
Contribution of Domain controllers in Integration of Windows 2008 with SSIM.
Best practices for integrating windows 2008 server with domain account.
How to install the Microsoft Windows Vista collector to remotely collect from a Windows 2008 Server Domain Controller via off-box agent
Authentication is failing when using a domain account with the Microsoft Vista and Microsoft Windows Server 2008 Collector
How to enable Windows Remote Management (WinRM) via Group Policy Objects (GPO) in Windows 2008 R2 to get Windows 2008/Vista Collector working.
msvista event collector 4.4 is not populating Windows Message and description field after March LU only on Windows 2008 SP2 using Kerberos
Kerberos authentication with Symantec Event Collector 4.4 for Microsoft® Vista and Microsoft Windows Server 2008
Collecting Events from a Windows 2008 R2 machine using the MS Vista Event Collector
Can the Windows Event collector v 4.3 collect the events from a Windows 2008 server?
The agentmgmt.bat utility does not work on Windows 2008
Creating event filter for User Name field for Windows Vista and Windows Server 2008 Collector
Symantec Event Collector for Microsoft Vista and Microsoft Windows Server 2008 missing description field
Configuring the MS Vista collector to pull events from a Windows 2008 R2 member server using a domain account and kerberos authentication using the HTTP protocol.
How to export a Windows 2008 certificate from a DC acting as CA, then importing the cert into the SSIM Agent
Configuring Symantec Event Collector 4.4 for Microsoft Vista and Microsoft Windows Server 2008 to Collect Events Using HTTP Transport With Domain Accounts
Authentication Types available with the Symantec Event Collector for Microsoft Vista 4.4
Active Directory Integration with Symantec Security Information Manager 4.7 using a Domain Controller Certificate
Windows Vista Collector is polling events only every 5 minutes
MS Vista 4.4 collector only uses one KDC in a domain environment with multiple domain controllers
How to delete a winrm Listener created with the quickconfig command
How to create a winrm listener on a custom port
Windows Vista Collector, CustomSD, SDDL, Security Log and how it works
Hope this helps you all!!