Yes they are in dual channel! CPU-Z confirms it
Both are in black slots on mobo. The motherboard manual has a misprint. Now I remember
This mobo is way outdated and I wish I could afford a new one with usb 3.0 but, I just don't need it.
This issue doesn't make sense though. I had the exact same kit in to begin and no issues. When I RMA'd the kit years later the new sticks caused the issue. Or at least the swapping of the sticks. To my knowledge they are the exact same. Same packaging, specs, and heatspreaders.