I am testing IntelliCAD 7.2.6363.0.P.VC9 x86 on windows 7 32bit.

This is the newest version of IntelliCAD as of Mar 21, 2014.
(IntelliCad is the first and only s/w installed on fresh install of windows 7 32 bit )

To make project 2d drawing on xy, yz, zx surface, i created some
shape (subtracting one box from another shape box) and copy it
to make 3 same entities.

0. generated entities. all 3 entities looks fine.

1. Look down from the top --> flatten on 1 st entity. It looks fine. 

2. Looks from the front --> flatten on 2nd entity. Strange lines extend from some of the edges.

3. Looks from the right side --> flatten on 3rd entity. This also generates strange lines extension.