Hi All,
 ART, I must admit the importing is really good and have been trying to break it.
Hopefully the following will provide some insight into the forgiveness built into Lazyturn.
 LAZYTURN IMPORT OF DXF FILES -  CAD DRAWING ERRORS 
1.A vertical line going up or down at the end of the profile is accepted but not required.
2.Additional elements  ie; multiple lines / one drawn under the other will cause an
  error " self intersection in master file" and no rendered graphics will be displayed.
3.Lines vertical or parrallel not connected to the profile ( even as close as .0001") are ignored.
4.A vertical line touching the profile will cause part of the profile to be ignored. The part ignored is
  is to the right of the line. If the line dosn't touch the profile then the line is ignored.
5.Two vertical lines touching the profile will cause rejection of profile to the left of the lines and 
   acceptance of the profile to the right of the two lines. I didn't check to see what happens as the 
   gap between the two vertical lines is increased to some value.
6.A break in the profile continuity on a straight horizontal line from .001" to about .11" still provides
  for a rendered image. With the break exceeding .11" to .2"  it acts as a break in the profile 
  and the left side of the profile is accepted / is the beginning of the rendered profile.
7. Space between intersecting circles .001" to .1"  still allows for a rendered graohic but a 
    horizontal line is created to complete the profile. Greater than .1" and the left side of the profile 
    is created as if it was the start of the profile at zero.
8.LazyTurn will reject lines in the lower half of the profile ( similar to 3 above ) including lines drawn 
   through the profile, but, no negative y values are allowed, and if they exist you will get an error
   message telling you so.
9.When partial circles ( arcs not touching / terminating at a common tangent point) overlap, the amount of 
   overlap modifies the profile similar to #7 above. Starting at a overlap tail of approx .050" only a partial 
   rendered profile will be produced. Note that #7 to #9 are for circles which would follow some basic shape 
   formula, thus a continous profile can be generated. This may not be the case for a non basic
   shape / non generic  math formula.
I am sure there are others that you can find and list. Lazyturn is very tolerant and seems to allow for 
many common errors but nothing beats doing it right the first time. Don't take this as gospel but rather 
what my testing with the attached file found.
RICH