dxf file import

[vextorspace]

Has anyone written any routines that read in dxf files? I'm having trouble with figuring out what units a file is in. There are it seems two units commands in the headers:

$INSUNITS and $LUNITS. Some files $INSUNITS is correct, others it seems incorrect, others it is weird.
correct:

$INSUNITS
70
    1

incorrect:

$INSUNITS
70
    0

weird:

$INSUNITS
350
CD

$INSUNITS is listed as the default units for drawing. $LUNITS is listed as the units for lines, coordinates, and such. It never seems correct and usually says something like feet when a drawing is in inches. Is there some other way of getting the units from the drawing?

The weird way claims to be a "soft owner handle" but I cannot find directions on how to resolve "soft owner handles".

Thank you,
--Douglas