After a fresh install of gtkradiant 1.4.0, I was disappointed to find it wouldn't open the manual. The console told me that sh wasn't able to execute openurl.sh. A simple "chmod 755 openurl.sh" fixed it. A couple other things (credits, changelog in the about dialog) won't open either until the change is made. I'd include an ebuild, except I don't know how to write them yet. Sorry.
Added a chmod a+x ${Ddir}/openurl.sh to the ebuild Fixed in CVS