UbuntuOne: no file transfer. GUI says file sync in progress, but u1sdtool --current-transfers reports errors

[Neil Robinson]

The UbuntuOne GUI keeps switching between "File Sync is disconnected" and "File sync in progress," but no file syncing appears to take place.
About 2Gb of files have already been uploaded, but nothing else will.
The folder structure of all the selected folders for syncing are shown on the web-interface, but the files themselves are not all uploading.

u1sdtool --current-transfers returns this error:

Traceback (most recent call last):
Failure: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

In addition, ubuntuone-syncdaemon process is using a lot of resources, and is now at 566MiB memory and 100% CPU.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: ubuntuone-client 2.0.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
ApportVersion: 1.23-0ubuntu3
Architecture: i386
Date: Fri Oct 21 15:01:50 2011
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
PackageArchitecture: all
SourcePackage: ubuntuone-client
UbuntuOneSyncdaemonExceptionsLog:

UbuntuOneUserSyncdaemonConfig:
 [__main__]
 log_level = DEBUG
UpgradeStatus: Upgraded to oneiric on 2011-10-16 (4 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.