Apple has released another minor update for iPhoto on the Mac today, bringing the version up to 9.5.1. Most notably, the updated includes a fix that caused print previews to appear garbled or otherwise render incorrectly on the screen.
From the release notes:
What’s New in Version 9.5.1
• Fixes an issue that could cause print previews to render incorrectly
• Includes stability and performance improvements
The update is available immediately via Software Update in the Mac App Store.