It seems to be PIX week here. I've had more requests for PIX configurations than anything! Anyhow, just a quick configuration to make a PIX correctly log to a SYSLOG server:
logging trap notifications (or warnings - notifications will send a ton of info)
logging facility 18
logging host inside/outside ip address
I also like to use the command logging device-id string name. This tags all messages in my syslog with an identifier so I know what device sent the message (by name rather than IP address).