It seems that console (command-line) use of inkscape.exe to export pdf/ps/etc fails with an absolute path on Win32. This happens with SVG files from at least Visio and Dia. (I haven't checked other input formats of flavors of svg.)

I use Cygwin on XP, and I discovered this when using dblatex for converting DocBook5 XML to PDF (when dblatex sees an SVG file referenced in XML it calls inkscape using absolute paths).

When I test inkscape alone it clearly succeeds on relative paths but fails on absolute paths.
(Note that if you want to try this yourself then you have to patch imagedata.py because it calls inkscape with in/out files mixed up -- see: http://sourceforge.net/tracker/index.php?func=detail&aid=3039592&group_id=72607&atid=535062)

I've tried your official/stable win32 installer v0.48, earlier v0.46, and nightly build 0.48+devel r10061 (Feb 21 2011). I also tried setting pythonpath, and other variables, and have made sure my shell knows which inkscape/python combo to use.

BTW, although I tried compiling the latest, some of Cygwin's packages are a bit behind and well, ain't gonna happen:
configure: error: Package requirements (gdkmm-2.4  glibmm-2.4 giomm-2.4 gtkmm-2.4 >= 2.10.0  gtk+-2.0  libxml-2.0 >= 2.6.11  libxslt >= 1.0.15  cairo  sigc++-2.0 >= 2.0.12    gthread-2.0 >= 2.0 libpng >= 1.2 gsl) were not met:
No package 'gdkmm-2.4' found
No package 'glibmm-2.4' found
No package 'giomm-2.4' found
No package 'gtkmm-2.4' found

So I won't be able to patch source and recompile :(

Thanks for any help, and I'll be glad to test new versions.

PS, please accept my apologies for not wanting to create an account on launchpad -- I have far too many accounts on systems around the Net, and I prefer to subscribe/unsubscribe from lists when possible.

--Jaz

/cygdrive/c/temp

$ inkscape -z -D --export-pdf=fig0.pdf testfile.svg   (or dir/subdir/testfile.svg , or ../subdir/testfile.svg, etc)

$ ls -l fig0.pdf
-rwx------+ 1 jazing None 18858 Feb 25 12:50 fig0.pdf

$ rm fig0.pdf

$ inkscape -z -D --export-pdf=fig0.pdf /cygdrive/c/temp/testfile.svg

** (inkscape.exe:7632): CRITICAL **: Inkscape::XML::Document* sp_repr_read_file(const gchar*, const gchar*): assertion `Inkscape::IO::file_test( filename, G_FILE_TEST_EXISTS )' failed

** (inkscape.exe:7632): CRITICAL **: Inkscape::XML::Document* sp_repr_read_file(const gchar*, const gchar*): assertion `Inkscape::IO::file_test( filename, G_FILE_TEST_EXISTS )' failed

** (inkscape.exe:7632): WARNING **: Specified document /cygdrive/c/temp/approval.svg cannot be opened (does not exist or not a valid SVG file)