The x11-wm/matwm2 homepage in the ebuild is not correct/no longer exists. Try this instead, please. http://squidjam.com/matwm/
03 Nov 2011; Kacper Kowalik <xarthisius@gentoo.org> matwm2-0.0.96.ebuild: Fix HOMEPAGE and SRC_URI wrt bug 379631 by Jesus Guerrero