Safari 5.01 on Macbook Pro 2010 13.3 with 10.6.4. This one locks up several times a day with no reason to be seen so far anyway. Yes Safari 5 locked up really nice but, not anywhere as bad as 5.01. Just doing normal net cruising I guess and there it goes locked up, spinning beach ball and all. No way to get to force quit. Only way out, is turn the Macbook off and start again. Also seen strange behavior in extensions that are clearly supposed to work on 5.01. What behavior. How about installing them, loading Safari 5.01 to to find nothing installed. Different for sure. I don't have any clue as to what does this simply because there are no messages. Just an unkind goodbye so too speak.