I have the exact same problem. When I press ESC on the black screen I can save the game. When I restart and try to load the saved game I can see the party standing in the main room of the Ebon Hawk (in the thumb nail in the load game dialog) - but the game hangs when actually loading the saved game half way.
I also have the ASUS SLI deluxe mobo with an XP4000+ but I use a GeForce 6800GT.
Any suggestions?
Before I entered the Ebon Hawk I did the fighting with the white sisters. I noticed that after the fight my two party members didn't follow back to the ship (they stayed in the arena). Maybe part of the problem?