No button graphics in subpics

[Sudum Gumudu]

Hi. I'm backing up a couple of interactive adult titles from the same series. The first one I've completed without problems, but the second one is more of a problem. In almost all of the video, there are buttons over video to get around to various parts of the title.
The first case was relatively easy, nice demuxed bmp:s with red button overlays on a blue background. On the second one, I'm unable to find button overlays anywhere. All of the bmp:s DIF4U/Vobsub demux is just a blue background with no button overlays whatsoever.
I've also been through all vob files with subrip. No button overlays. They got to be there somewhere. I've searched the forum to the best of my ability and read the post http://forum.doom9.org/showthread.php?s=&threadid=51810 , but I'm unable to figure out if the stuff mentioned there is applicable to my problem. Has anyone encountered this before?

Some info:

SST:

st_format 2
Display_Start non_forced
TV_Type NTSC
Tape_Type NON_DROP
Pixel_Area (0 477)
Directory D:\Rip\MP\VTS05\subs\VTS_05_VSUB_P1A2-00-F
Subtitle VTS_05_VSUB_P1A2-00-F-English
Display_Area (0 2 719 479)
Contrast (15 15 15 0)

PA (0 0 255 - - - )
E1 (255 0 0 - - - )
E2 (0 0 0 - - - )
BG (255 255 255 - - - )

SP_NUMBER START END FILE_NAME
Color (15 5 15 9)
Contrast (0 0 0 0)
0001 00:00:00:-1 00:00:36:28 VTS_05_VSUB_P1A2-00-F-English_0001.bmp
0002 00:00:36:29 00:01:16:02 VTS_05_VSUB_P1A2-00-F-English_0002.bmp


IDX:

# VobSub index file, v7 (do not modify this line!)
#
# To repair desyncronization, you can insert gaps this way:
# (it usually happens after vob id changes)
#
# delay: [sign]hh:mm:ss:ms
#
# Where:
# [sign]: +, - (optional)
# hh: hours (0 <= hh)
# mm/ss: minutes/seconds (0 <= mm/ss <= 59)
# ms: milliseconds (0 <= ms <= 999)
#
# Note: You can't position a sub before the previous with a negative value.
#
# You can also modify timestamps or delete a few subs you don't like.
# Just make sure they stay in increasing order.


# Settings

# Original frame size
size: 720x480

# Origin, relative to the upper-left corner, can be overloaded by aligment
org: 0, 0

# Image scaling (hor,ver), origin is at the upper-left corner or at the alignment coord (x, y)
scale: 100%, 100%

# Alpha blending
alpha: 100%

# Smoothing for very blocky images (use OLD for no filtering)
smooth: OFF

# In millisecs
fadein/out: 50, 50

# Force subtitle placement relative to (org.x, org.y)
align: OFF at LEFT TOP

# For correcting non-progressive desync. (in millisecs or hh:mm:ss:ms)
# Note: Not effective in DirectVobSub, use "delay: ... " instead.
time offset: 0

# ON: displays only forced subtitles, OFF: shows everything
forced subs: OFF

# The original palette of the DVD
palette: e63f07, 6a70e0, 11eb10, e63f07, 7e7e7e, bebebe, 14bef3, 0000df, faff1a, 000070, 067506, 731f03, 095f78, 750975, 7c950b, ffffff

# Custom colors (transp idxs and the four colors)
custom colors: OFF, tridx: 0000, colors: 000000, 000000, 000000, 000000

# Language index in use
langidx: 0

# English
id: en, index: 0
# Decomment next line to activate alternative name in DirectVobSub / Windows Media Player 6.x
# alt: English
# Vob/Cell ID: 2, 1 (PTS: 0)
timestamp: -00:00:00:066, filepos: 000000000
# Vob/Cell ID: 2, 2 (PTS: 37037)
timestamp: 00:00:36:970, filepos: 000000800

[ultimatebilly]

I don't have a clue, but maybe it's a different angle you are in? I heard that multi-angles are quite common with these types of movie...
Just an idea...

[Sudum Gumudu]

Well, it is. But the subpics from both angles look the same, and besides, the subpic demuxing of the first title worked.
I've resorted to Plan B now however. I made new button overlays using elements from the first titles overlays. After some fiddling to align them properly, they seem to turn out rather fine. We'll see when it's finished. It's still mysterious though.