Comment 3 for bug 377697

Further to this it may be wise to look at how Update-Manager interacts with power management. When Update Manager is active, it prevents the system from entering 'Suspend'.

I can understand this - say the updates being applied could potentially prevent suspend from working. However it actually makes this paper cut much more severe since you can wind up in a state where you started an upgrade, ran out of power and then couldn't even suspend and resume later to complete it!