I was evaluating R# 6.0 and the evaluation expired as I wait for my company to purchase licenses. Thus I had to downgrade to 5.1.3 until the licenses come through. Unfortunately I can no longer run NUnit unit tests. I click the "Run Tests" link in the gutter, the Unit Test Sessions window opens, but it displays two empty sessions and says "No open unit test sessions." This previously worked great. I'm using VS2010 on Win7 x64 with .NET 4.0. R# also gives me an error when I try to apply the keyboard shortcuts via Resharper -> Options -> Visual Studio Integration -> Apply button -- not sure if that is related or not.