I looked at some of the builds at
rpmfind.net. The base versions for the Mandriva and Livna versions is the May 31, 2008, release. The Mandriva "cooker" version is r28387 which includes some patches dated as late as September 16th. I know a few months can be a long time in mplayer-land, but these are both fairly up-to-date. Freshrpms has a version from September as well.
All of these are, I believe, more recent than the current Ubuntu build. On my 8.10 (Intrepid) box, the current mplayer release is 1.0-rc2svn28238. I don't have the source .deb handy to see how recent the code is, but I must say I don't have any problems watching modern anime releases with that version except for the issue of ordered chapters. That problem doesn't really matter to me; in fact, I enjoy the absence of repeated OP/ED segments when watching a number of episodes in one sitting.