Well - in case anyone else runs across this... I found the answer here: http://forums.autodesk.com/t5/Visual-Basic-Customi
In short, SetWindowToPlot expects the values in DCS (Display Coordinate System). DCS is not always equal to WCS - so you have to translate the points from WCS to DCS. I am still a bit puzzled by the fact that 95% of the time (if not more) DCS == WCS.
Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register
Start with some of our most frequented solutions to get help installing your software.