I got this error while using Team Build today (from the event log):
TF53010 ... Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression ... sp_InsertProjectDetails ...

According to http://geekswithblogs.net/cyoung/archive/2006/03/09/71820.aspx, this is a bug in the RC (yes, I still haven't had a chance to goto RTM). I'm not sure if it's fixed in RTM or not. At any rate, my issue was that I had 2 shared projects (projects that are included in more than 1 solution). The second shared project references the first. These seems to cause Team Build to die, with no error in the build log. The event log has more details. So, I added a hack of a file reference instead of a project reference for that solution and things seem to build.