Sequence dependent tests are, unfortunately, something you'll need to give up on if you're to make proper use of NCrunch. There's some more details about this in the documentation.
I don't mean that the tests should run in a specific order but that only one test has to be run at a time. My current client has a codebase with a lot of integration tests. The DB is setup before each test. so running more than one test simultaneously will screw up the DB.
Ahh - so you're experiencing issues with parallelisation then?
The best way to solve this would be to make sure your integration tests are properly attributed with the NCrunch.Framework.ExclusivelyUsesAttribute. In this way, you can still have your unit tests running in parallel but let the integration tests run serially.
There's also some other options - it's well worth having a read of the documentation around parallel execution.