comparing my pre-existing account with my test account, one difference is the presence of a .Xmodmap in my main account, which I was using to map the media keys in hardy. Moving aside my .Xmodmap brings up a correct set of keybindings in the session. So that accounts for that part of the breakage on my side, leaving me with only the Fn+F4 (sleep) and Fn+F12 (hibernate) buttons failing to work.
comparing my pre-existing account with my test account, one difference is the presence of a .Xmodmap in my main account, which I was using to map the media keys in hardy. Moving aside my .Xmodmap brings up a correct set of keybindings in the session. So that accounts for that part of the breakage on my side, leaving me with only the Fn+F4 (sleep) and Fn+F12 (hibernate) buttons failing to work.