What I had to do was disconnect Tomboy from Ubuntu One.
The re-connect it.
This caused the PC to be authenticated again (with a different serial number).
I then deleted the old entry for the PC
Tomboy sync now works.
I know there were updates to the servers recently. Does Tomboy cache URLs? If so, I guess this could happen again.
I think I may have fixed it.
What I had to do was disconnect Tomboy from Ubuntu One.
The re-connect it.
This caused the PC to be authenticated again (with a different serial number).
I then deleted the old entry for the PC
Tomboy sync now works.
I know there were updates to the servers recently. Does Tomboy cache URLs? If so, I guess this could happen again.