Session "WbadminInBuiltTracing" failed to start with the following error: 0xC0000035

I'm getting the following error:

Log Name:   Microsoft-Windows-Kernel-EventTracing/Admin
Source:    Microsoft-Windows-Kernel-EventTracing
Date:     5/17/2010 11:04:48 AM
Event ID:   2
Task Category: Session
Level:     Error
Keywords:   Session
User:     ****
Computer:   ****
Description:
Session "WbadminInBuiltTracing" failed to start with the following error: 0xC0000035
Event Xml:<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"><System><Provider Name="Microsoft-Windows-Kernel-EventTracing" Guid="{B675EC37-BDB6-4648-BC92-F3FDC74D3CA2}" /><EventID>2</EventID><Version>0</Version><Level>2</Level><Task>2</Task><Opcode>12</Opcode><Keywords>0x8000000000000010</Keywords><TimeCreated SystemTime="2010-05-17T18:04:48.898886000Z" /><EventRecordID>45</EventRecordID><Correlation /><Execution ProcessID="4816" ThreadID="2800" /><Channel>Microsoft-Windows-Kernel-EventTracing/Admin</Channel><Computer>****</Computer><Security UserID="****" /></System><EventData><Data Name="SessionName">WbadminInBuiltTracing</Data><Data Name="FileName"></Data><Data Name="ErrorCode">3221225525</Data><Data Name="LoggingMode">2</Data></EventData></Event>

Does anyone know what this is or how to prevent it from occurring?

I'm running Windows Server 2008 R2.

Thanks much,
James