There have been other odd issues with older versions of M3 in some CV situations, which upgrading M3 have cleared up.  Perhaps you might try upgrading to Ver. .062, which cleared up a problem for me and some others. 

I'll give that a try.

Sorry, arcs i meant

That makes more sense!

Derek

try checking plasma mode in the configuration screen. short line segments will tend to slow down the toolpath with plasma mode on short line segmented curves.