I agree, the grippy must be in a different location on the log cabin Creative Grids ruler than the 4 1/2 x 4 1/2 square.
Another thought, when I have loads of HST to trim down and square up I prefer the Bloc Loc ruler. I am not the type that needs every size ruler made - I have the 6 1/2 x 6 1/2" Bloc Loc HST ruler and use it for all HST's up to that size. Love how it secures the block for precise trimming.