I bought Dawn Of War: The Complete Collection long ago but I didn't play any game online, only skirmish or LAN with my brother (which is legal I think, as we didn't play game online), but recently I started playing online because of my friend. My brother wanted to play too.
He bought new CDs so he can play online with us. He uninstalled DC and installed it again with new CD and new CD key. He also used new codes for DoW and WA to unlock other five races following this guide (as I did before to save space, but with my codes).
But when he enters the online room when I'm already there, I get kicked with message that someone else used my CD key. Same for him when I connect again. But we use different CDs and different CD keys, and we cannot play together online with other people.
Please post solution as soon as you can.