[MPlayer-users] -ss sometimes jumping dramatically in some mpg/mpeg2 files

[Heitzso]

I have an application that uses "-ss" feature of [g]mplayer heavily.
The video files being viewed are quasi dvd/mpeg2 files generated
by transcode/mplex/etc. from DV files.  When gmplayer starts up
the mpg files are reported as:
    video = mpeg-ps, mpeg2, mpegpes, libmpeg2
    audio = ac3, liba52

PROBLEM is for maybe2/3rd of the 60 or so mpeg2 files gmplayer does
a reasonable job of "-ss" into them.  However, for the other third
gmplayer can seek correctly up to a magic point, and
then jumps a great distance for the next seek.  For example
    "-ss 11:45.5" seeks correctly to 11:45.5, but
    "-ss 11:45.6" seeks incorrectly to 25:36,
JUMPING to a couple of seconds before the end of the video.

You see  this also when running without the "-ss" then clicking
on the slider that positions the video --- you click say 40% along
the slider and all of a sudden the slider jumps to the end,
then back to the beginning, and then the video stops playing. 

Version of mplayer: 1.0pre7-3.3.5

CLUES?  This is hurting me.  I'm 4 months into a project that is
relying on gmplayer being able to seek into an mpeg2 file +/-
a couple of seconds.  I had assumed all was well because first
few mpeg2 files I experimented with worked okay.  So I'll spend
the time deep in the code if I have to to try to fix this problem.
But I'd appreciate some pointers first whether a daily cvs will
fix this, or whether all of the seek processing is happening deep
in the libmpeg2 file, etc.

THANKS
Heitzso