How to Change Build Pathway for TFS2008

Question

We are using VS2010 (Beta2) and TFS2008. I know this portion of the buildlog.txt controls the pathway:

Using "Message" task from assembly "Microsoft.Build.Tasks.v3.5, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
Task "Message"
  BuildDefinition=CI
Done executing task "Message".
Task "Message"
  BuildDefinitionId=**3**
Done executing task "Message".
Task "Message"
  BuildUri=vstfs:///Build/Build/1584
Done executing task "Message".
Task "Message"
  ComputerName=**ALICE**
Done executing task "Message".
Task "Message"
  TeamFoundationServerUrl=http://dev-svr:8080/
Done executing task "Message".
Task "Message"
  TeamProject=Science
Done executing task "Message".

An older build successfully calls:

DeleteWorkspaceTask TeamFoundationServerUrl="http://dev-svr:8080/" BuildUri="vstfs:///Build/Build/1584" Name="**ALICE_3**" DeleteLocalItems=True

A newer build unsuccessfully calls:

DeleteWorkspaceTask TeamFoundationServerUrl="http://dev-svr:8080/" BuildUri="vstfs:///Build/Build/1679" Name="**ALICE_3_**" DeleteLocalItems=True

My Question is where can I begin to trace the extra "_"?

Thanks,