When trying to create a new Team Project on my test TFS 2010 basic installation I got the error

Time: 2011-07-05T11:43:36
Module: Engine
Event Description: TF30162: Task “BuildTask” from Group “Build” failed
Exception Type: Microsoft.TeamFoundation.Client.PcwException
Exception Message: Multiple identities found matching workspace name ‘TYPHOONfbb296e15246421e9fc8d25e9d128512typhoon (VC)’ and owner name ‘BLACKMARBLEfez’. Please specify one of the following workspace specs:
TYPHOONfbb296e15246421e9fc8d25e9d128512typhoon (VC);BLACKMARBLEfez
TYPHOONfbb296e15246421e9fc8d25e9d128512typhoon (VC);BLACKMARBLEfez
Stack Trace:
   at Microsoft.VisualStudio.TeamFoundation.Build.ProjectComponentCreator.ExecuteInternal(ProjectCreationContext context, XmlNode taskXml, Boolean validationOnly)
   at Microsoft.VisualStudio.TeamFoundation.Build.ProjectComponentCreator.Execute(ProjectCreationContext context, XmlNode taskXml)
   at Microsoft.VisualStudio.TeamFoundation.ProjectCreationEngine.TaskExecutor.PerformTask(IProjectComponentCreator componentCreator, ProjectCreationContext context, XmlNode taskXml)
   at Microsoft.VisualStudio.TeamFoundation.ProjectCreationEngine.RunTask(Object taskObj)
--   Inner Exception   –
Exception Message: Multiple identities found matching workspace name ‘TYPHOONfbb296e15246421e9fc8d25e9d128512typhoon (VC)’ and owner name ‘BLACKMARBLEfez’. Please specify one of the following workspace specs:
TYPHOONfbb296e15246421e9fc8d25e9d128512typhoon (VC);BLACKMARBLEfez
TYPHOONfbb296e15246421e9fc8d25e9d128512typhoon (VC);BLACKMARBLEfez (type MultipleWorkspacesFoundException)

Exception Stack Trace:    at Microsoft.TeamFoundation.VersionControl.Client.InternalCache.GetWorkspace(Guid repositoryGuid, String name, String owner)
   at Microsoft.TeamFoundation.VersionControl.Client.InternalCache.Merge(XmlNode xmlOnDisk, InternalWorkspaceConflictInfo[]& removedConflictingWorkspaces)
   at Microsoft.TeamFoundation.VersionControl.Client.InternalCache.Save(XmlNode inputXml, XmlNode outputXml, InternalWorkspaceConflictInfo[]& removedConflictingWorkspaces)
   at Microsoft.TeamFoundation.VersionControl.Client.InternalCacheLoader.SaveConfigIfDirty(InternalCache internalCache, InternalWorkspaceConflictInfo[]& conflictingWorkspaces)
   at Microsoft.TeamFoundation.VersionControl.Client.Workstation.UpdateWorkspaceInfoCache(String key, VersionControlServer sourceControl, String ownerName)
   at Microsoft.TeamFoundation.VersionControl.Client.Workstation.EnsureUpdateWorkspaceInfoCache(VersionControlServer sourceControl, String ownerName, TimeSpan maxAge)
   at Microsoft.TeamFoundation.Build.Controls.VersionControlHelper.CheckinFiles(VersionControlServer versionControl, Dictionary`2 localPathsToServerPaths, String checkinComment)
   at Microsoft.VisualStudio.TeamFoundation.Build.ProjectComponentCreator.CheckinFiles(ProjectCreationContext context, VersionControlServer versionControl, List`1 templates)
   at Microsoft.VisualStudio.TeamFoundation.Build.ProjectComponentCreator.ExecuteInternal(ProjectCreationContext context, XmlNode taskXml, Boolean validationOnly)

This turns out to be another version of the local cache refresh issue I blogged about recently. The issue was I had deleted a couple of team projects on my TFS server via the TFS Administration Console, but my local VS2010 copy did not know as the cache had not been refreshed. Unloading VS2010, reloading it so the local cache was refreshed and then the create new project works fine