http://www.wh-hms.uni-ulm.de/~mfcn/gnomeradio returns 404. New homepage is at http://projects.gnome.org/gnomeradio/ . BTW, sources are unavailable too, so probably it's time to update SRC_URI too
For SRC_URI I filled upstream bug report: $URL
tarball is in our mirrors, and homepage seems to work HOMEPAGE="http://projects.gnome.org/gnomeradio/" SRC_URI="mirror://gentoo/${P}.tar.gz"