Manually installing ubuntuone-client and ubuntuone-client-tools; killilng ubuntuone-client-applet and launching from menu worked for me.
Ubuntu 9.04 Firefox 3.0.11
Manually installing ubuntuone-client and ubuntuone- client- tools; killilng ubuntuone- client- applet and launching from menu worked for me.
Ubuntu 9.04
Firefox 3.0.11