I have recently upgraded to VS2010 Premium and Resharper 5.1.3000.12. Its test runner will now not execute MS Tests.
The dialog shows up but nothing happens.
By default resharper is configured to use shallow-copy assemblies being tested.
What you need to do is go to Resharper -> Options
From left side pane select tools -> Unit Test
Uncheck Shallow-copy assemblies being tested
Then try running, Thats working for me.