Comment 4 for bug 44615

There's several parts to this;

  a) Whether we can detect the the keypress
  b) Whether the software stack (eg. gnome-power-manager) knows what to do with it
  c) Whether your laptop actually Suspends successfully.

Can you include the output from running:

  lshal -m

and we can see if the action is getting that far. You can test the Suspend manually from a console by running:

  sudo pmi action suspend