Ah! If I understood you correctly, you have also confirmed that this problem is not with the LW prefs (I guess we knew that too when deleting the LW prefs folder didn't work earlier).

FWIW, installing OS X updates will be useful if one of those updates make your new LW cease to work. If all updates work correctly, then you'll know more about what files to compare with the non-working account. Right now it will be difficult to compare OS X prefs since there are so many OS X differences to compare.