P.S. hey, my account on this forum is 12 years old and this is actually my first post... you can see how important this topic is to me
We expect never to hear from you again... 
And shame on your for using a proprietary graphics API. You need to take a lesson from Paradox Interactive and port your engine to OpenGL to make cross platform releases possible.
That's a little crude, no?
I mean I don't dislike Linux in particular, but if the developers are comfortable with the current working of directX9, that's the way it is.
I guess its probably both cheaper and quicker to use the current systems.
Sincerely
~ Kongdej