Failed to connect to 'locahost' - Event ID 0 on ePDM server

Running a new install of SolidWorks ePDM 2012 SP3 on Windows Server 2008 R2. All databases and vaults are installed on same server. Access to the databases works fine through SQL Server Management Studio and access to the vaults via the ePDM Client works fine. I am also able to connect to the databases using the SQL Server administrative 'sa' account.

Everything appears to be running ok, but I am getting constant events in the application event viewer:

- System

    - Provider

     [ Name]  SolidWorks Enterprise PDM Database Server

   - EventID 0

     [ Qualifiers]  0

    Level 2

    Task 0

    Keywords 0x80000000000000

   - TimeCreated

     [ SystemTime]  2013-03-19T20:58:56.000000000Z

    EventRecordID 23764

    Channel Application

    Computer server.abcxyz.com

    Security

   - EventData

     Failed to connect to 'localhost'. Error:Could not access the item in the database. 

These events occur twice roughly every two minutes.

I have gone through the Troubleshooting problems with the PDMWorks Enterprise database server troubleshooting guide. I also turned on logging for the database server according to the guide, but the log file shows no connection errors at all.

Can anyone suggest a fix?