Yeah, dual channel worked with one in purple and one in green (slots 1 and 2) like Nubius said... but the dogonned book is just so contradictive. I mean, who publishes that BS. I went to find it and right away it said something about "3 combinations (see table below)" and the table was above and I knew right there, this book is just half-assed. Anyway, I guess, like most things, you learn the most from actually experimenting and messing around with it and NOT just reading that manual.