I have found out the cause of the problem: a possibly broken vm86old() call, like my strace log said. I will try updating to 2.4.20 (using .19 with patches from gentoo, i think it worked in .18) Maybe it is related to glibc instead according to that mdk9 user (i hope he keeps using the same kernel for his tests) To the mplayer developers, i am using the latest glibc (2.3.1) I will keep testing. We are tracking this bug at: http://bugs.gentoo.org/show_bug.cgi?id=15346