I'm using xUnit 2.2 and I have some test classes marked as [Trait("Category", "UsesNetworkFiles")]. This worked fine in NUnit (with [Category("UsesNetworkFiles"]) to skip expensive tests when I'm running tests at home, but after switching to xUnit, NCrunch doesn't seem to detect the test category the same way. Is there a reason for this that I'm missing?

Yes it did show the correct category, and that lead me down the path to dig a little deeper. I tried running the tests 3 times on two different machines, tried resynchronize/rebuild/rerun without any luck. One thing I hadn't tried was deleting the NCrunch cache directory, so I shut down VS and deleted it. When I fired VS back up the tests were excluded as expected! Thanks so much for the quick reply, sorry about the false alarm. I guess things got out of sync from switching testing frameworks.