Wheelman replied:

Allan, both bits of info you recieved were correct, confused?
Earlier steel radials were not necessarily built with 4,6 or 8 plies in the casing, but were ply rated, which goes back to the old days when the casings were often reinforced with cotton.
These days most tyres are built as to their stated plies. Bear in mind that the sidewalls of most tyres are always only 2 ply, its the tread area that has the extra plies. In earlier ply rated tyres, heat was a major cause of early case failure,caused by under inflation and high operating speeds, and counter rotating can induce higher operating temps if the tyre is badly worn from mis alignment, incorrect camber and toe-in for the vehicle suspension type, driving conditions etc, and balance, ie scalloping.
To get maximum life from your muddies, you may well have to counter rotate, as they are prone to scalloping on the edges, depending on whether your alignment is suitable to our road camber, as many vehicles as standard are not. Unfortunately many manufacturers negate to identify this, and a lot of new vehicles have more positive camber on the left front than the right, ever wonder why your toyota, nissan, jeeps and plenty of other jap 4wd's seem to love running off the left all the time. (Great for the biggest 4WD market in the world, U.S.A.)
In the end, get your advice from a reputable wheel alignment/suspension specialist, as often the local specialist is the guy who the 4WD dealers get to fix their alignment problems, he sees these problems and tyre problems all day long.
To finish, I say definately rotate directly front to rear and vice versa every 10-15,000kM, and if you don't need to counter rotate, then don't, if you do, then you may have a problem that is causing the specific wear on that tyre, but counter rotating may get you a bit more life from an incorrectly worn tyre.