"With specific amounts of free space on your drive, you may see a screen that tells you have insufficient space to create game data even though there is plenty of free space on your drive." He remains decidedly non-specific regarding said "specific amounts," but at least the man provides a workaround. If you encounter the problem, "either delete or add about 500MB of data to your hard drive and the problem will go away." You'll know you've won when you can actually play the game.