Nokia 1680 / 1681, "data transfer not possible. Check data connection"

[geoffrey]

Trying to set up my Nokia 1681c to sync with U1 mobile. Error message when I try to connect (selecting Server sync on the phone, and accept connection to Funambol): "data transfer not possible. Check data connection".
What does that mean? Apologies if this is not a U1 bug, but I can't figure out where the problem is.

Here are the instructions I got from the U1 page:
Setup instructions

   1. Go to Menu and choose Settings
   2. Select Configuration
   3. Select Personal configuration settings
   4. Press Options, then Add New
   5. Select Synchronisation
   6. Set Account Name: Funambol
   7. Set Server Address: http://syncml.one.ubuntu.com/
   8. Set User name: XXXXXXX
   9. Set Password: XXXXXXXX
  10. Select Contacts database
  11. Set Database address: card
  12. Go back once
  13. Set Use preferred access point: Yes (make sure you have a working internet connection; if you don't have one, contact your mobile provider)
  14. Go back once
  15. Highlight Funambol
  16. Press Options and select Activate
  17. Go back to Menu and choose Settings
  18. Select Connectivity (on some devices Sync and backup)
  19. Select Data transfer (on some devices Server sync)
  20. Select Server sync [BUG APPEARS HERE]
  21. Mark Contacts
  22. Save the changes

[Martin Albisetti (beuno)]

We're addressing these problems in a more systemic way.