In xsane-0.30-2.i386.rpm , the post-install script contains the line:
ln -s ../../../bin/xsane /usr/lib/gimp/1.0/plug-ins/xsane
which is an attempt to make xsane work as a gimp plugin. That's great,
except there's one "../" missing, so this line makes a symlink to
/usr/lib/bin/xsane instead of /usr/bin/xsane. The line should really be:
ln -s ../../../../bin/xsane /usr/lib/gimp/1.0/plug-ins/xsane
Then it will work :-)
Check out xsane-0.47-2 in rawhide whenever it gets updated. It's now fixed.