I think Ryukishi delibelatery set several (false ?) solutions to the riddle.
Jan-Poo's attempt to solve the riddle is also an interesting and quite coherent one :
http://forums.animesuki.com/showpost...postcount=1137
So I can't believe that LORDU is a coincidence ! And if it's really a coincidence I think Ryukishi is aware of that.