Dear Jay,

no problems here with a "G4-P57_MirrorDoor" (dual processor 1.25MHz, 
OS 10.4.11, SecUpd2009-005PPC).

I've only recently downloaded (no automatic update) Safari 4.1 and I 
use it without any problems (no start or shutdown issues with the Mac 
either).

Hope you soon will find a stisfying solution!

Best
-- 

                   Herbie

          ------------------------
          <http://www.gluender.de>