Steps to reproduce:

1. Create a test project which contains a test list.
2. Check in the project to the TFS.
3. Rename the test list and save the project.
4. Check in the project again.

Actual: The project is marked as dirty however the test list is not presented in the Check in window. The file is left in a pending mode.
Expected: The test list with the new name is checked in successfully. 

The workaround is to close and reopen the project. After that you can rename again the test list and it will be checked in successfully.