When I surf web for several hours or so, my iBook slows down. If I reboot it, Safari gets up to the normal speed. I am guessing some types of log files or some other memory/virtual memory management are causing the slow down on Safari's speed. I have not noticed this type of slow down on my PBs. My iBook is functioning well except for this issue and I am wondering if I can clean up some clutters which are causing Safari to slow down without rebooting. I tried log in and log out; but it did not fix this issue. My iBook runs 10.4.3. My PBs run 10.3.9 (Al 15), 10.4.2 (Al 12) and 10.4.3 (Ti).