At some point I had problems with tests parallel execution as those tests used files and there were some locking conflicts (only in case of parallel execution). When I swithced to ContinuosTests (Mighty Moose) the problem gone as tests execution is parallelized only per assemlby in Mighty Moose. May be it would be reasonable to add settings ParallelizeTestsNotInOneAssembly and even ParallelizeTestsNotInOneTestClass (which would be enough in my case).
Edited 28 Jun 2012 16:41 UTC