Ubuntu 11.04 comes with an in-built comprehensive testing application which will run all kinds of tests on your system to check if it is working properly.
From the search box in Unity interface, type system and select System Testing from the options displayed.(Or through Applications > System > System Testing).
This will bring up a wizard which will allow you to select various kinds of tests that need to be run, selecting all will take a bit of time for the test to complete.
Follow the on-screen instructions regarding whether to allow a specific test to run, whether it ran correctly or skip it altogether.
Here are some of the tests that will be done :
Once all the tests are complete, a neat report will be generated showing what was tested and how the overall results turned out :
By the way, troubleshooting specific system areas becomes very easy because of the System Testing tool as you can only test something you need and see how it performs.