Recurring error after successful update to 11.10

[PaddyIndigo]

I'm afraid I only saw the I upgraded, and now I have this error entry after I upgraded, otherwise I may have avoided this.

I've just upgraded from 11.04 to 11.10, and I'm getting an error that i don't understand;

There was a problem opening the address book "Ubuntu One" - the message returned was:
Cannot open Book: Could not create DesktopcouchSession object

, see attached image.

Any ideas?

Apologies if I'm duplicating an existing query, I failed to find anything resembling in several searches.

Thanks
Pat