Mobo is quite new... released this summer. Sometimes conflicts/issues don't crop up until it's in wide use...they cannot test every possible combination of parts. Since it's brand-new... contact Asus support with the problem.
Re: the OEM copy... just don't "volunteer anything" when you call-- I can't see that it's an issue, and the operator you speak to will probably not be able to tell. Just tell them you've upgraded your hardware... they may ask what you upgraded. Tell them it was a custom-build (the truth, after all) and you need to reactivate.
What CD do you own? is it SP1 or SP2 ? while you should still be able to download the service-packs from the Knowledge-base... I don't know if reactivation would become an issue with an older CD...that would not be fun.
Maybe someone you know has SP2 on CD-- it is not licensed --by itself so it is legal to use any copy. Says so right on my CD copy.
All you can do is give it a shot.
