"Apparently this problem only appears after an upgrade.It seems I never got this kind of problem with fresh installs, and people here appear to be in the same situation..."
Not true. I have this bug, with the very same dbus-monitor reports as in #8, on my fresh Xubuntu 12.10 install on a Thinkpad W510. As others have mentioned, this seems to happen after one (or maybe several) suspend-resume cycles. In fact, I've had this bug for years, I think starting from a fresh install of Ubuntu 11.04. Sad really...
@hadware, #27:
"Apparently this problem only appears after an upgrade.It seems I never got this kind of problem with fresh installs, and people here appear to be in the same situation..."
Not true. I have this bug, with the very same dbus-monitor reports as in #8, on my fresh Xubuntu 12.10 install on a Thinkpad W510. As others have mentioned, this seems to happen after one (or maybe several) suspend-resume cycles. In fact, I've had this bug for years, I think starting from a fresh install of Ubuntu 11.04. Sad really...