Hi, thanks for sharing this issue.
NCrunch doesn't perform any special actions on the SynchronizationContext. Can you share any details around which test framework you are using? Do you also experience this problem with any test runner other than NCrunch?
NCrunch can introduce a different execution order for your tests. Because most other test runners don't do this, the change in order can sometimes cause tests to
fail intermittently if they are state dependent. It's difficult for me to suggest with any certainty whether this is causing your problem, but I thought I'd mention it as worth a look, since it can be a common cause for similar sounding issues.