Apple has updated Aperture 3 to version 3.0.3, which is intended to improve stability and fix a number of issues, including the following areas:

• Applying adjustments such as Retouch or Chromatic Aberration
• Creating and using Raw Fine Tuning presets
• Viewing, adding and removing detected faces
• Switching target printers and paper sizes when printing
• Duplicating Smart Albums
• Repairing and rebuilding Aperture libraries
• Reconnecting referenced files
• Working with GPS track files in Places
• Searching for keywords in the Query HUD or Keyword Controls

Complete release notes on the fixes are available on Apple’s website here.  Aperture 3.0.3 is available for download from Apple’s website here, or via OS X Software Upate.