Yep, definately check your build. I was whitescreening away untill I found out, had to use the 38xx build for my 3870 (which in hindsight does sound a bit logical don't you think?).
And bytheway, when you finally get your screen, don't give up yet when you want to try to save your game. It won't do it! You have to make a quake/id1 directory in your ipaq storage folder and copy an empty text file called s0.sav .
Hope that helps if you have an ipaq 38xx