In http://hg.mozilla.org/comm-central/rev/5e42e6537169, I commented out the ExitTest() function of the idcheck test, because it throws away all prefs but this makes all following test that need to open windows fail as the popup blocker stops them from opening their windows. We should either look very carefully into this and decide we never need to clean up those mail prefs, or correctly go and only clean up those, maybe with adding a function to mailTestUtils.js that again uses the account manager to delete the account we created.

I'm not that convinced that the problem is actually test_idcheck.xul. Ideally, the testing environment would be created as default pref values, so that every test can easily throw away everything it doesn't know about, eg. *before* it runs. Currently, running (chrome) tests successfully depends upon the order the tests are run, because you can't be sure about the state of the system a specific tests gets! Luckily(!), this didn't break up to now (to our knowledge at least)...

That said, we should, of course, clean up as far as possible here as well...