"Can't restore job state due to data type mismatch: Job type=group, Data type= at /usr/share/perl5/Event/ExecFlow/Job.pm line 478." when starting dvdrip-master

[Mossroy]

Binary package hint: dvdrip

Here is how I got this error :
I used the clustering feature of dvd::rip successfully on some DVDs. I had many projects in the state "finished".
I then exited dvd::rip, and launched it again. When I tried to open the cluster control window, dvdrip-master failed to start.
I saw this error message when starting dvdrip-master manually in a terminal

I saw that somebody else had a similar error :
http://www.exit1.org/archive/dvdrip-users/2007-08/msg00002.html
The workaround he gives worked for me : deleting or renaming ~/.dvdrip-master/master.conf

Anyway, I kept my master.conf file and tried to find what was giving the error message.
It looks like it comes from one particular .rip file (the problem disappears if I remove it from the "project_order" list, and it appears if it is the only member of this list).

It is the file 00000016-riptest-dvd1.rip (see attached files).
In comparison, you'll also find the attached file 00000019-riptest-dvd1.rip that does not have the problem (it is another chapter of the same DVD) : if I put this one in the master.conf, dvdrip-master starts successfully.
Anyway, I did not find what was wrong in the file when comparing them.

I'm using Ubuntu Lucid, with all current updates.
dvd::rip is in version 1:0.98.11-0ubuntu2 (latest available in standard repo)

Here are the dependency versions of dvdrip :

  -------------------------------
  dvd::rip 0.98.11
  transcode 1.1.5
  ImageMagick 6.5.7
  ffmpeg SVN-r0.5.1-4:0.5.1-1ubuntu1,
  xvid4conf non installé
  subtitle2pgm 0.3
  lsdvd 0.16
  rar 3.90
  mplayer cvs
  ogmtools 1.5
  dvdxchap 1.5
  mjpegtools 1.9.0
  xine 0.99.6
  fping 2.4
  hal 0.5.14
  -------------------------------