I was having an almost identical error when plugging a usb key, and finally did found that dbus policy was saying both one thing and then the opposite, commenting out the opposite fixed it for me:
More precisely in /etc/dbus-1/system.d/hal.conf it says: <!-- Allow anyone to invoke methods on the Manager and Device interfaces --> <policy context="default"> ... <allow send_interface="org.freedesktop.Hal.Device.Volume"/> and later: <!-- Default policy for the exported interfaces --> <policy context="default"> <deny send_interface="org.freedesktop.Hal.Device.SystemPowerManagement"/> <deny send_interface="org.freedesktop.Hal.Device.VideoAdapterPM"/> <deny send_interface="org.freedesktop.Hal.Device.LaptopPanel"/> <deny send_interface="org.freedesktop.Hal.Device.Volume"/> <deny send_interface="org.freedesktop.Hal.Device.Volume.Crypto"/> </policy> that I edited to become: <!-- Default policy for the exported interfaces --> <policy context="default"> <deny send_interface="org.freedesktop.Hal.Device.SystemPowerManagement"/> <deny send_interface="org.freedesktop.Hal.Device.VideoAdapterPM"/> <deny send_interface="org.freedesktop.Hal.Device.LaptopPanel"/> <!-- deny send_interface="org.freedesktop.Hal.Device.Volume"/ --> <!-- deny send_interface="org.freedesktop.Hal.Device.Volume.Crypto"/ --> </policy> So I just commented out the last two deny lines (note the -- at the end too! ) ** Changed in: dbus (Ubuntu) Status: New => Confirmed -- dbus.error.accessdenied https://bugs.launchpad.net/bugs/235134 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs