Comment 16 for bug 544525

The problem is now more less fixed after an update (today update for me).

The list of updated/installed packages by the update manager are:

Upgraded the following packages:
acpid (1.0.10-5ubuntu2) to 1.0.10-5ubuntu2.1
capplets-data (1:2.30.0-0ubuntu4) to 1:2.30.1-0ubuntu1
dvipng (1.12-3build1) to 1.12-3ubuntu0.1
empathy (2.30.0.1-0ubuntu3) to 2.30.1-0ubuntu1
empathy-common (2.30.0.1-0ubuntu3) to 2.30.1-0ubuntu1
file-roller (2.30.0-0ubuntu1) to 2.30.1.1-0ubuntu2
gedit (2.30.0git20100413-0ubuntu1) to 2.30.2-0ubuntu1
gedit-common (2.30.0git20100413-0ubuntu1) to 2.30.2-0ubuntu1
gimp (2.6.8-2ubuntu1) to 2.6.8-2ubuntu1.1
gimp-data (2.6.8-2ubuntu1) to 2.6.8-2ubuntu1.1
gnome-control-center (1:2.30.0-0ubuntu4) to 1:2.30.1-0ubuntu1
gnome-settings-daemon (2.30.0-0ubuntu6) to 2.30.1-0ubuntu1
grub-common (1.98-1ubuntu5) to 1.98-1ubuntu6
grub-pc (1.98-1ubuntu5) to 1.98-1ubuntu6
indicator-sound (0.2.2-0ubuntu1) to 0.2.3-0ubuntu1
language-pack-en (1:10.04+20100421) to 1:10.04+20100422
language-pack-en-base (1:10.04+20100421) to 1:10.04+20100422
language-pack-gnome-en (1:10.04+20100421) to 1:10.04+20100422
language-pack-gnome-en-base (1:10.04+20100421) to 1:10.04+20100422
libgimp2.0 (2.6.8-2ubuntu1) to 2.6.8-2ubuntu1.1
libgnome-window-settings1 (1:2.30.0-0ubuntu4) to 1:2.30.1-0ubuntu1
libgtksourceview2.0-0 (2.10.0-0ubuntu1) to 2.10.1-0ubuntu1
libgtksourceview2.0-common (2.10.0-0ubuntu1) to 2.10.1-0ubuntu1
libkpathsea5 (2009-5) to 2009-5ubuntu0.1
libnautilus-extension1 (1:2.30.0-0ubuntu4) to 1:2.30.1-0ubuntu1
libsoup-gnome2.4-1 (2.30.0-0ubuntu1) to 2.30.1-0ubuntu1
libsoup2.4-1 (2.30.0-0ubuntu1) to 2.30.1-0ubuntu1
linux-generic (2.6.32.21.22) to 2.6.32.22.23
linux-headers-generic (2.6.32.21.22) to 2.6.32.22.23
linux-image-generic (2.6.32.21.22) to 2.6.32.22.23
linux-libc-dev (2.6.32-21.32) to 2.6.32-22.33
nautilus (1:2.30.0-0ubuntu4) to 1:2.30.1-0ubuntu1
nautilus-data (1:2.30.0-0ubuntu4) to 1:2.30.1-0ubuntu1
nautilus-sendto-empathy (2.30.0.1-0ubuntu3) to 2.30.1-0ubuntu1
pm-utils (1.3.0-1ubuntu1) to 1.3.0-1ubuntu2
python-ubuntuone-client (1.2.1-0ubuntu1) to 1.2.1-0ubuntu2
rhythmbox (0.12.8-0ubuntu3) to 0.12.8-0ubuntu4
rhythmbox-plugin-cdrecorder (0.12.8-0ubuntu3) to 0.12.8-0ubuntu4
rhythmbox-plugins (0.12.8-0ubuntu3) to 0.12.8-0ubuntu4
software-center (2.0.2) to 2.0.3
texlive-binaries (2009-5) to 2009-5ubuntu0.1
transmission-common (1.92-0ubuntu2) to 1.92-0ubuntu2.1
transmission-gtk (1.92-0ubuntu2) to 1.92-0ubuntu2.1
ubuntuone-client (1.2.1-0ubuntu1) to 1.2.1-0ubuntu2
ubuntuone-client-gnome (1.2.1-0ubuntu1) to 1.2.1-0ubuntu2

Installed the following packages:
linux-headers-2.6.32-22 (2.6.32-22.33)
linux-headers-2.6.32-22-generic (2.6.32-22.33)
linux-image-2.6.32-22-generic (2.6.32-22.33)

I have no idea of which one is THE one...