Horizontal Curvature Drawing Taking time

Hi,

I am working on a rail project currently where i need to recreate alignment of an existing railway line. I used regression tools for doing the same. I imported the survey data which has centreline of tracks as polylines. Converted poly line to Horizontal geometry. Then using option Geometry-> Utilities -> Assign Names, created points for regression. Added the points to Regression points and when i use "Horizontal Curvature Diagram Option" the PRT engine takes very long time and creates a diagram which is very much lengthier than the centre line. Can any one please point me out what is going wrong and the right way to do it.