As noted in http://support.wdc.com/knowledgebase/answer.aspx?ID=9796 the “Complete Drive Test” fails when the Energy Saver is set to “Put HD to sleep when possible”, when running WD Drive Utilities v. 2.0.5.18
However, I had already spent QUITE SOME TIME worrying about the state of my drive and rerunning the test, before finding above page. I’m sure you can detect in the settings in OS X that this sleep mode is enabled, so please pop up a warning that that setting prevents proper running of this test!
