Good grief! The solutions look almost as bad as the disease. I've been an IBM laptop fanboy for some time but now... since Lenovo took over... I've not been too confident. This just confirms my reticence.
My acer laptop has the same wonky behaviour with the screen brightness. I think it may
have something to do with the hibernate/sleep/screensaver software within Gnome.
As for your issue of the screen locking up when trying to resume from suspend mode.... are you sure the screen isn't locked? When this occurs try typing in your user password and see if it doesn't solve the problem. If this works you need to go into:
System --> Preferences --> System --> Power Management
System --> Preferences --> Look and Feel --> Screensaver
and change the appropriate settings (oh, btw, in the Power Management GUI at the "On AC Power" and "On Battery Power) tabs... note the tick box for "Dim display when idle" option. You may wish to uncheck it as it was checked by default during my install)