Hey Tom, been watching your post for a few days. It looks like a low speed dross. The cuts themselves look good. Is it possible your machine is not running the actual speed listed in the code? I found that inadvertantly when we changed over to our new system. Our old system was not actually running the speeds it was told too. The new system has almost no dross when cutting at book speeds were as the old looked like your cuts, lots of dross but to be fair the cuts were nice, just lots of extra clean up. I thought that was the way it was supposed to be! LOL
Can you do a speed test to see if it has somehow got out of whack, maybe binding up somewhere?