the dxf file extents is not being set properly.

\\\$EXTMIN
 10
1.000000000000000E+20
 20
1.000000000000000E+20
 30
1.000000000000000E+20
  9
\\\$EXTMAX
 10
-1.000000000000000E+20
 20
-1.000000000000000E+20
 30
-1.000000000000000E+20

see the attached files