Re: BobCad Beginner error I am sure.
A couple of things. First, there's a BobCAD sub-forum here, http://www.cnczone.com/forums/bobcad-cam/ so posting BobCAD specific questions there would help smooth the process out.
Next, in almost every case, it's a good idea to attach a zipped copy of your .bbcd file to the post. That contains the geometry in question, all your settings, etc. It's invaluable in diagnosing problems. Just save the file, right-click on it and choose <Send to> [Compressed, (zipped) Folder]. Then, using the Advanced editor, upload it and attach it to your post.
Your problem sounds like it might be an issue with the drawing geometry, but a look at the actual file would help nail it down.
Luke
"All I'm trying to find out is the fellow's name on first base" -- Lou Costello