It sounds to me like SCAL2 isn't really working with any open paths after all. I think that the reason it is "working" with lines is that when a line doubles back on itself to close the path you don't see it.
You can always change an open path to a closed one by doing stroke to path (or Illustrator equiv) but the problem is that you can't see in a PDF or Inkscape or Illustrator when a path is not closed.
I'm not enough of an AI geek to know about plugins and such, but I did find these 2 add ons that allow you to select open paths (and therefore identify them).
for earlier PC versions and Mac up to CS4(I think) http://rj-graffix.com/software/plugins.html (you want the select one)
for CS4 Windows http://maps.aridocean.com/scripts_en.php
Also sometimes PDFs or svgs not made for cutting have adjacent paths separate but touching and need to be joined with the nodes tool to make a closed path. It may be faster to just click inside the shape with the paint bucket instead (it works without needing a bitmap copy).
For an example of this see the svgs generated by this http://www.red-bag.com/engintools/calccone_svg.php
and my mini tutorial on the paint bucket here http://cleversomeday.wordpress.com/2009 ... -tutorial/
And if you haven't seen HeatherM's tutorial on converting PDFs in general you need to. The rest of us have been doing it the hard way.
http://imagesbyheatherm.wordpress.com/2 ... es-to-svg/
Maybe we need an advanced checklist for pdfs. The Inkscape version would look something like this
open
select all and read status bar
if "image" ->trace
if "paths" and/or "groups" ->
select what you want from groups using control click and shift control click
invert selection
delete the rest
remove score lines or replace them with dashed lines
check for open paths
if they are lines in space ->stroke to path (this will also work for dashed score lines)
if they are closed shapes made up of adjacent open paths (4 separate lines forming a square, for instance)->create closed path with paint bucket or join end nodes with nodes tools
select all > path > object to path
for scal1 > ungroup
for scal 2> ungroup and regroup by color so they will be layered in SCAL2
Wow, sorry to be so long winded. I'm gearing up for the Georgia Tech game today and I guess I've really got my nerd on. LOL