Same here. Exactly the same problem started after begin a sync in Ubuntu One.
$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 10.10 Release: 10.10 Codename: maverick
$ uname -a Linux xavix1 2.6.35-27-generic-pae #48-Ubuntu SMP Tue Feb 22 21:46:58 UTC 2011 i686 GNU/Linux
$ dpkg -l "gnome-panel" ii gnome-panel 1:2.30.2-1ubuntu3
$ dpkg -l "*wnck" ii python-wnck 2.30.0-1ubuntu5
Same here. Exactly the same problem started after begin a sync in Ubuntu One.
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.10
Release: 10.10
Codename: maverick
$ uname -a 27-generic- pae #48-Ubuntu SMP Tue Feb 22 21:46:58 UTC 2011 i686 GNU/Linux
Linux xavix1 2.6.35-
$ dpkg -l "gnome-panel"
ii gnome-panel 1:2.30.2-1ubuntu3
$ dpkg -l "*wnck"
ii python-wnck 2.30.0-1ubuntu5