LinuxQuestions.org - spumux dvdauthor error

Can someone put me right. I am trying to create a simple menu for two 'movies' using dvdauthor/spumux, but get an error when I run dvdauthor: "ERR: That form of jumping is not allowed"

My menu is created as a jpg and converted to mpg with:

$ jpeg2yuv -n 50 -I p -f 25 -j background.jpg | mpeg2enc -n p -f 8 -o background.m2v

and multiplexed with: mplex -f 8 -o menu-1.mpg background.m2v menu_audio.mpa

Here is my spumux xml (sub-pictures-2b.xml):

<subpictures>
<stream>
<spu
start="00:00:00.00"
image="main2.png"
select="main2s.png"
highlight="main2h.png"
autoorder="columns">
</spu>
</stream>
</subpictures>

Here is my command line, and result:

$ spumux sub-pictures-2b.xml < menu-1.mpg > menu.mpg
DVDAuthor, version 0.6.4. Build options: gnugetopt
Send bugs to <dvdauthor-users@lists.sourceforge.net>

w=720, h=576, bd=8, ct=6
png had 2 colors
w=720, h=576, bd=8, ct=6
png had 2 colors
w=720, h=576, bd=8, ct=6
png had 2 colors
Found EOF in .sub file.
warning, sub on line 0 starts before 4s, (some players won't show it)
max_sub_size=994
private sector size 37
skipped 0 bytes of garbage
max_sub_size=994
1 subtitles added, 0 subtitles skipped, stream: 32, offset: 0.18

Here is my dvdtree xml (dvdtree-2-buttons-1.xml):

<dvdauthor dest="dvd">

<vmgm>
<menus>
<pgc>
<post>
jump titleset 1 menu;
</post>
</pgc>
</menus>
</vmgm>

<titleset>
<menus>
<pgc>
<button> jump title 1; </button>
<button> jump title 2; </button>
<vob file="menu.mpg" pause="inf"/>
</pgc>
</menus>

<titles>
<pgc>
<vob file="movie1.mpg"/>
<post>
call menu;
</post>
</pgc>
</titles>

<titles>
<pgc>
<vob file="movie2.mpg" />
<post>
call menu;
</post>
</pgc>
</titles>

</titleset>

</dvdauthor>

Here is my dvdauthor command:

$ dvdauthor -x dvdtree-2-buttons-1.xml
DVDAuthor, version 0.6.4. Build options: gnugetopt
Send bugs to <dvdauthor-users@lists.sourceforge.net>

INFO: dvdauthor creating VTS
STAT: Picking VTS 01

STAT: Processing menu.mpg...

INFO: Video pts = 0.184 .. 2.184
INFO: Audio[8] pts = 0.184 .. 11.824
INFO: Audio[32] pts = 0.184 .. 0.184
STAT: VOBU 2 at 0MB, 1 PGCS, 0:00:02
INFO: Generating VTSM with the following video attributes:
INFO: TV standard: pal
INFO: Aspect ratio: 4:3
INFO: Resolution: 720x576
INFO: Audio ch 0 format: mp2/2ch, 20bps

STAT: Processing movie1.mpg...
STAT: VOBU 128 at 25MB, 2 PGCS, 0:01:00
INFO: Video pts = 0.184 .. 67.144
INFO: Audio[8] pts = 0.264 .. 67.224

STAT: Processing movie2.mpg...
STAT: VOBU 252 at 53MB, 2 PGCS, 0:02:00
INFO: Video pts = 0.184 .. 59.224
INFO: Audio[8] pts = 0.184 .. 59.224
STAT: VOBU 264 at 56MB, 2 PGCS, 0:02:06
INFO: Generating VTS with the following video attributes:
INFO: TV standard: pal
INFO: Aspect ratio: 4:3
INFO: Resolution: 352x288
INFO: Audio ch 0 format: mp2/2ch, 20bps

STAT: fixed 2 VOBUS
STAT: fixed 264 VOBUS
INFO: dvdauthor creating table of contents
scanning dvd/VIDEO_TS/VTS_01_0.IFO
INFO: Creating menu for TOC
STAT: VOBU 0 at 0MB, 1 PGCS, 0:00:00
WARN: video resolution was not autodetected
WARN: video format was not autodetected
WARN: aspect ratio was not autodetected
INFO: Generating VMGM with the following video attributes:
INFO: TV standard: ntsc
INFO: Aspect ratio: 4:3
INFO: Resolution: 720x480

ERR: That form of jumping is not allowed

Any help would be appreciated .......