[dvd::rip] Subtitles being cut after some minutes?

Hi all,
I am using dvdrip to encode from dvd images of old dvd's but I am having
problems when generating the subtitles in Vosub format. All the
subtitles seem to be cut after less than ten minutes of the movie.
Actually the file that is cut is the .idx, so that when I am playing
them with mplayer or vlc, the subtitles disappear when the idx finishes.
See for example, this idx for a 2 hours movie:

---------------
# VobSub index file, v7 (do not modify this line!)
#
# Generated by MPlayer 0.90pre6-2.95.3 (subtitleripper)
# See <URL:http://www.mplayerhq.hu/> for more information about MPlayer
# See <URL:http://vobsub.edensrising.com/> for more information about
Vobsub
#
size: 720x480
palette: 101010, 2b2b2b, ebff0b, 1c1c1c, 7d7d7d, b4b4b4, 0bb5ea, ec14ed,
ebff0b, 0d007f, 0c7b0c, 7e2a0e, 0d637c, 7e127e, 7d960c, ebff0
b

# Language index in use
langidx: 0

id: enen, index: 0
timestamp: 00:02:54:924, filepos: 000000000
timestamp: 00:02:56:793, filepos: 000000800
timestamp: 00:02:59:762, filepos: 000001000
timestamp: 00:03:02:866, filepos: 000001800
timestamp: 00:03:12:609, filepos: 000003000
timestamp: 00:03:16:212, filepos: 000004000
timestamp: 00:05:08:291, filepos: 000004800
-------------------------

I have repeated the process with many times with all the movies, and all
of them get cut the same way. I am attaching the content of dvdrip's log
and the generated idx file... Any clues on why this is happening?

Thanks for the help!
/Nacho

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       ,,,
      (o o)
--ooO--(_)---Ooo-----------
Curiosity is the very basis of education and if you tell me that
curiositykilled the cat, I say only the cat died nobly. - Arnold
Edinborough 
--oo0--------0oo-----------
Log.txt
Description: Text document
Movie-sid00.idx
Description: Text document