1. Open a DOS prompt in the LyX bin directory and type sed --version. If it reports version 3.something, go to <http://sourceforge.net/project/showfiles.php?group_id=23617&package_id=>http://sourceforge.net/project/showfiles.php?group_id=23617&package_id= 16429, download sed 4.0.9 (or the latest 4.x release), and install that version of sed.exe over the one in the bin directory. Then try running configure again.
I never got this to work; I replaced sed.exe with newer 4.0.9 and also added the required libiconv2.dll and libintl3.dll in the lyx bin directory, but configure fails with usage errors from sed. Does sed replacement actually work for you (i.e. you're sure cygwin's sed is not used instead)? Maybe I'm missing something somewhere...
Regards,
Milos
