I was getting lots of segmentation violations, and cover surface failures while using a poly arc (instead of lines). I found that the resolutions were not uniform, and that there was a disconnect of endpoints by.000038-.000049 ". enough to cause some hassles.
If you are getting odd failures, and using groups, follow this sequence to aid from failures.
1) Primary objects with same (super fine) resolution
2) group-medium is default- edit to superfine
3) (my work was offsetting, so:) Offset products, verify resolution to all same within edit object window
4) layout/ group as needed, edit to needed resolution