Strange lineweight effects in certain arcs using certain linetypes.

[BigDumbWeirdo]

I'm getting this strange effect whenever I use the linetype shown. As you can see, the global width of the polyline is set. Anyone have any ideas as to why? Couple of things I've noticed:

Only this linetype seems to do it (this is the only linetype with a symbol in it, specifically, '%%c').

I also noticed elsewhere, where there's a smaller arc on a line with the same linetype, there was what looked like a branch of the polyline shooting off to one side, although it had not vertices.