Hey jfchapman,
I have checked through my settings and have found a few that you might want to check on your system. They are:
FILLMODE = 1
PLINEGEN = 0
PLINETYPE = 2
SPLFRAME = 0
If you type in the text shown above on your command line, and then check the default setting, OR set it to the values that I have (listed above) that may help you get what you need.
Hope this helps,
Paul