Well, the system install doesn't appear to be corrupted since it only affects the one account. If deleting the Finder's preferences doesn't help, it must be another one of the user's preference files that are corrupted, though I wasn't aware that the Finder used any additional plist files.
Is it possible to just create a new account and move all of the user's files over (Documents, Music, Movies, etc)? Sorry that I can't be of more help.