Just out of curiousity, do you consider the dash 8 or the Jetstream to be swept wing aircraft?

Haven't flown either.
Do they have a yaw/roll couple PROBLEM as opposed to exhibiting a tendency?
Getting back to swept wings, the B757 could exhibit a slight tendency to a roll cycle on approach (about 1 cps) which we put down to PIO.

Edited to say: M(F)S please don't think I am challenging your aerodynamic knowledge. I was probably incorrect to state <<Straight wing aircraft do not suffer from dutch roll>> but I have never flown nor heard of a straight wing aircraft going into service which suffered from dutch roll to the extent of the early swept wing aircraft of the B707 era.

I have been following this discussion for a while now. Without doubt, I follow it with interest but the more I read the more I come to the conclution that there is perhaps no simple explanation to the 'dutch roll question'. Not without a deep analysis of all aspects that affect an aircraft during a sideslip. I don't feel my aerodynamic knowledge is sufficent for such an analysis but I find your's most interesting. :ok: