Just installed Avid Symphony 6.0.1 on my MacBook Pro (running OS X Lion 10.7.3)

When I start up Avid, I get:

"Segmentation fault" in thread "MainThread", at address      0x0

then Avid quits.

There is a known issue with SN 6.0.1 and 10.7.3, you should install 6.0.1.1. It's available on the Download Center in the Avid Editor Patches section.

The fix for this is to go into permissions for your system drive (Macinstosh HD>Get info) and set "everybody" to "read/write".