The 10.6.5 Update is recommended for all users running Mac OS X Snow Leopard and includes general operating system fixes that enhance the stability, compatibility, and security of your Mac, including fixes that:
improve reliability with Microsoft Exchange servers
address performance of some image-processing operations in iPhoto and Aperture
address stability and performance of graphics applications and games
resolve a delay between print jobs
address a printing issue for some HP printers connected to an AirPort Extreme
resolve an issue when dragging contacts from Address Book to iCal
address an issue where dragging an item from a stack causes the Dock to not automatically hide
resolve an issue with Wikipedia information not displaying correctly in Dictionary
improve performance of MainStage on certain Mac systems
resolve spacing issues with OpenType fonts
improve reliability with some Bluetooth braille displays
resolve a VoiceOver issue when browsing some web sites with Safari 5
For detailed information on this update, please visit this website:http://support.apple.com/kb/HT4250.
For information on the security content of this update, please visit:http://support.apple.com/kb/HT1222.

Also there is Free SOPHOS anti-virus application just released.
      <www.sophos.com/freemacav>

It is currently checking my 1.5 million files. Essential now.
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Regards from brianF
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