Problem with SATA Command Queuing

I noticed that within Windows Device Manager under the SATA options you could enable command queuing. Since I have a hard drive that supports it, I thought I'd give it a try.

Now I was under the impression that this was supposed to increase performance, however I think it hurt it significantly. Am I doing something wrong with it?

Google: http://www.google.com.au/search?hl=en&q=raptor+sata+command+queuing&meta=

I've looked through several links and all seem to say what I believe, that I should experience a performance increase...

There is a performance decrease (significant) when I switch the mainboard to command queuing.

This is my issue. And I do have a 74gig WD Raptor, of which should support CQ.