[curt.clifton]

OF seems to get progressively slower to launch with extended use. I think this is because of the way OF stores its database. Essentially it stores an optimized version of the database, plus a list of all the changes made since the last time the database was optimized. The database is optimized when 1) the database format changes in a new OF build, 2) you restore from backup, or 3) you choose File --> Rebuild Database.

I suggest Backing Up your database, then trying File --> Rebuild Database.

I'm not sure if my guess is correct, but the rebuild seems to help on my system (still on Tiger until 10.5.1). Please report back if the rebuild helps on your machine.