Total time to run Tests

Hello,
We have a couple of build configurations setup in Teamcity. On both configurations there is a build step to run unit tests using nunit. For both configurations there seems to be a large discrepancy between the total time it takes to run the tests. Under the tests tab it reports that the total time to run the tests is 2 minutes and 42 seconds. But if you look at the build log the total time for the nunit step is 5 minutes and 54 seconds. My first assumption is that the test tab does not include the time for TestFixureSetup, TestFixtureTeardown, Setup, and TearDown methods. The thing is I have know way of know what is consuming so much time for the unit test build step.

What can we do to figure this out?

Thanks in advance,

Damien