very weird problem with encoding on linux

In essence, no matter how I encode a file (any file), be it mencoder, transcode, or avidemux, i get a movie that's 100% made of keyframes(!). I think I tried everything, and still haven't got slightest idea why this is happening. Are there some config files, or environmental variables that xvid library uses? I can provide some additional info ofc. I'm running Gentoo Linux, with everything latest versions: xvid 1.1.3; transcode 1.0.6; mplayer - marked as mplayer-1.0_rc2_p25993-r1 and ffmpeg directly from SVN It would be nice if someone could send me his libxvidcore.so.4.1; so I could check if it's the build, or something in my system. Thanks in advance.

It is most likely a problem in your XviD libraries. How about using lavc MPEG-4 instead?

What's that? Is it as good as xvid?