FRom what I understand is that the white screen is produced because the game doesn't properly clear its memory, thus loading the last games data into a new game and producing a white screen. Try rebooting your computer, that usually works for me, if that doesn't find the save files on your pc and delete them.
The samethin happened to me more then once
Elemental was barely running on my old Athlon2400 rig, now it rocks.. except that the world map is all black !!! wtf ? I mean there is no cloth map at all, it's black emptiness, on which the features and units appears normally... I had the same problem, I fixed it by turning off the anti-aliasing.
I fixed the black map by turning off the anti-aliasing, but the white screen still continues to randomly appear upon the creation of a new game
Everytime I start a game, no matter what video settings I choose or game creation settings (soverein, empire, etc.) the world map is totally black exept special tiles and units or the screen is all white. http://dl.dropbox.com/u/5133500/debug.err Here is what it looks like (black map):