[Dvdauthor-users] spumux 0.7.0 - errors trying to create a smple menu

[<gh...@ma...>]

Trying to create a simple DVD menu with:
  spumux "menu_buttons.xml" < "menu.mpg" > "menu2.mpg"

Output and information on the input listed below
What does the error mean?
Appreciate any clues, hints, references, etc.
Thank you!
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
DVDAuthor::spumux, version 0.7.0.
Build options: gnugetopt imagemagick iconv freetype fribidi fontconfig
Send bug reports to <dvd...@li...>

INFO: default video format is NTSC
STAT: 0:00:00.000
INFO: Picture highlight_buttons.gif had 2 colors
INFO: Picture select_buttons.gif had 2 colors
INFO: Constructing blank img
INFO: Autodetect 0 = 178x280-191x294
INFO: Autodetect 1 = 178x310-191x324
INFO: Autodetect 2 = 178x342-191x356
INFO: Autodetect 3 = 178x372-191x386
INFO: Autodetect 4 = 178x404-191x418
INFO: Pickbuttongroups, success with 1 groups, useimg=1
WARN: Incorrect pack header
INFO: Skipped 53234 bytes of garbage
....
  (above line repeated about 50 more times, with varying amounts of "garbage")
....
INFO: 0 subtitles added, 0 subtitles skipped, stream: 32, offset: -0.00
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
file "menu_buttons.xml":

<subpictures format="ntsc">
   <stream>
   <spu force="yes" start="00:00:00.00"
        transparent="0000FF"
        highlight="highlight_buttons.gif"
        select="select_buttons.gif"
        autooutline="infer">
   </spu>
   </stream>
</subpictures>
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
"menu.mpg" is a 4-second silent video with a background image and
text describing the menu choices.  Did not include due to size,
but here is the tail from "ffprobe menu.mpg":

Input #0, mpeg, from 'menu.mpg':
   Duration: 00:00:03.95, start: 0.523344, bitrate: 1075 kb/s
     Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 720x480 [SAR  
200:219 DAR 100:73], 104857 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97  
tbc
     Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 128 kb/s
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The files "select_buttons.gif" and "highlight_buttons.gif"
each contain a column of solid circles with a transparent
background.  The circles serve as buttons aligned with
text in the input file "menu.mpg."  The files were created
with the script:

convert -size 720x480 xc:blue -fill $FILLCOLOR \
-draw 'circle 184,286 190,286' \
-draw 'circle 184,317 190,317' \
-draw 'circle 184,348 190,348' \
-draw 'circle 184,379 190,379' \
-draw 'circle 184,410 190,410' \
-colors 2 \
tmp.gif
convert -transparent blue tmp.gif $FILENAME

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