Comment 5 for bug 501323

As I understand the results you got from 'apport-collect 501323' , a new window or tab should have opened in your browser executing this, or you could copy the link to the authorization page; but you did not seems to have given the permission to apport-collect to run on this web page.

I suggest you retry 'apport-collect 501323' but take time to authorize apport in the web page, before continuing.

Also, https://wiki.ubuntu.com/DebuggingGNOMEPowerManager seems to suggest that you try:
dbus-send --system --print-reply --dest="org.freedesktop.Hal" /org/freedesktop/Hal/devices/computer org.freedesktop.Hal.Device.SystemPowerManagement.Suspend int32:0

at the $ prompt of Accessoires/Terminal... If it does the same problem that way, that would suggest that this is a kernel bug rather than a gnome-power-manager bug. Maybe I will mark this bug to the kernel too, so that apport-collect also collect information for a kernel bug if that becomes one.