I am using Snow Leopard and my mac is offline. The freezing actually started when I updated from leopard to Snow leopard in 2009. There is a shutdown log that lists every hard shutdown - always around the 20th and or on Monday.
I have the internet setup (dial-up). In safe mode - apple Iwork and Ilife does not fully load - but amazingly I can use adobe photoshop no problem. There should be no difference between safe and regular startup because I do not have any plugins or startup items. I launch my pen-pad by just launching the actual app - rather than having it auto load.
One of the logs seems to be looking for kext files - I know there was one problem on the last itunes update for Snow Leopard - but there never was a fix.
I have set everything I can find for no auto connect - no auto update - no synchronization.