There is important update for Lab Management 2010, that fix many problems
This update contains fixes and updates to the Lab Management functionality to improve performance, stability, usability and diagnostic information. The following is a list of major fixes in this update:
- Improves performance for Lab Management Workflow Wizard.
- Improves performance for running automated test cases on Network Isolated Lab environments.
- Fixes an issue in which a Test Controller service account that is the same as a Lab Service account causes issues with environment capabilities.
Note: You need to install this update on all of your client machines running Microsoft Test Manager, Test Controller, Team Foundation Server, build and virtual machines. This update is required to use the final release version of the Visual Studio 2010 Lab Management functionality. Please make sure that required software components from the release version of Visual Studio 2010 are installed before you install this update.
There is also a good link for troubleshooting Lab Management