In PBEM it tracks your CD key so you are unable to play PBEM with the same CD Key. I think this is because of some sort of 'cheating' workaround issue. Though I could be wrong.

My laptop has had problems with playing Dom2 as well. Mostly I think it's a graphic or video card problem, as my particular laptop has specific drivers as opposed to general PC ones. It does work but it has a lower framerate than my PC (PC has about 75+, Laptop ~25) but I could only get it to work in Windowed mode and by using some of the information found in the technical thread about laptops.