Look for new stuff in the frame transforms menu ('h'). Option 'c' is new; shoving everything below it down a letter.
Also note in the UI visuals and system toggles, menu 'u', option 'c' has been added; shoving everything below it down a letter.
I bet drlava gets what this is all about without any explanation!
If you have data that you know has retraced lines in it, you can either blank them by choice by applying "c blank equivalent segments", or you can let the optimization option do that for you. By default this is considered too expensive.
Turns out, if you know your data has a lot of retracing in it, looking for it and removing it saves time! Otherwise, it takes a lot more time.
http://hacylon.case.edu/laser/LaserBoy/LaserBoy_07_15_2008.zip
It still isn't perfect. (Imagine that!) The example data that drlava sent me has dots in the corners and I need to figure out how to find and eliminate them!
James.