each and every time you try to merge MPlayer you get an error about default.tar.bz2 digest being wrong.
Try deleting it in /usr/portage/distfiles, and then let portage download it again. It still works fine here (after the new digest got commited by Daniel).
I think the best solution is to mirror default.tar.bz2 under another name. We need something with a real version number on it to solve this problem.
uploaded default.tar.bz2 to ibiblio as default-skin-0.1.tar.bz2 and updated the digest and ebuild.