3ds Max :: Extract Splines From Geometry

i used to do a lot of spline extracting from geometry, mostly to use sweep modifier to modeling. But i usualy got a problem when i do that, some of the splines are "flipped" (or reversed), causing a problem in sweep geometry. In attached image, i extracted the splines from the faces below, and when i apllied the sweep, some of the splines get a different result. I tried to collapse the spline, reverse, flip the geometry normals, reset xform, create another spline and attach the extracted one, and nothing solved the problem. What i usualy do is to detach part of the spline and apply the modifier twice.