[MPlayer-users] Trying to trim off the beginning of a *.VOB file.

[mplayerhq.hu at jamesplace.net]

When I try:
   mplayer dvd://1 -chapter 26 -ss 59 -dvd-device /movie 

It starts playing exactly where I'd like it to, everything works great. 
However, when I try:

   mplayer dvd://1 -chapter 26 -ss 59 -dvd-device /video -dumpstream -dumpfile 
Trimmed.vob

It always starts at the beginning of chapter 26 not at the 59-second offset 
into that chapter. 

Am I doing something wrong?
Is there a better way to accomplish this?

Thanks much.