Comment 30 for bug 283573

This is a workaround:
If you have many tomboy notes, delete some of them or put the old ones to an archive!

I experienced the crash in Ubuntu 10.10, started "gnome-do --debug"

After the message
  [Debug 10:30:21.805] [UniverseManager] Reloading item source "Tomboy Notes"...
gnome-do crashed with the exception
  Unhandled Exception: System.Exception: Message body length mismatch: 16000 of expected 20125

I moved all notes from ~/.local/share/tomboy to a backup place and restartet tomboy.
Gnome-Do ran stable.

First assuming a corrupted note as cause, I put the newest notes back to the folder and found a number of 250 tomboy notes being fine for gnome-do's tomboy-plugin. I think it's not only the number but also the size of notes that matters, but made no further tests here.