In previous releases, if you used code contracts and code coverage, your code coverage might be understated due to distortions in the analysis of the code inserted by the code contracts rewriter.
I tested the new version and it fixes this. So now, code coverage behaves as I expect. If you see partial coverage in some contracts, remember to write automated tests to exercise those alternate paths that cause contract failure.
Get the release at http://social.msdn.microsoft.com/Forums/en-US/codecontracts/thread/85db6b1f-fb92-4b34-9212-362de066c2cc.