Apple has released Keynote 5.1.1 which addresses issues when working with large Keynote presentations on OS X Lion.
Keynote 5.1.1 also includes improvements in stability and accessibility for Keynote.
This update is recommended for users of Keynote 5.1.
System Requirements:
• Mac OS X 10.6.6 or later
• Mac OS Lion 10.7 or later
Detailed information on this update and individual application changes here.
Keynote 5.1.1 is available via Software Update and also as a standalone installer.
More info and download link (29.94 MB) here.