something along the way has screwed up my iphoto. i installed the new iphoto 6 and although it opens my photos i cant edit them or anything else. i wont open them in the big window at all. the guys at the apple store couldnt figure it out either. i have now messed with it and have no doubt deleted some important part of iphoto as i tried to load my old i photo that i have backed up in my lacie external drive. well it is just basically broken so i was wondering if i backed up everything i have now then wipe my disc and reinstall tiger if that might fix this problem? if so, how do i go about doing this? do i delete everything currently on my hard drive? by just putting in the tiger disc will it overwrite everything? is there some special way to wipe clean my HD first? help!