Hey Don.
I see you were using 2 different profiles for the sweep.. Yes, when i used the tangent circle construction method, with 2 different profiles for the sweep, i get the little wiggle also.. The wiggle happened at the segment points of the curves and caused the sweep to pause and twsit on itself..

I fixed this with the original construction curves by running "rebuild" on that curve at a .001 tolerance to remove that segmented area and then the sweep followed the path well..

Sounds like you switched methods and got results already... This is FYI.