i'm having tons of computer problems today. i'm running leopard, and i did an erase/install to fix a previous issue and it was working fine until i ran a software update (because my restore disk is fairly old and i wanted to make sure everything is up-to-date) and when i restarted, it was stuck on the install screen without it loading for a really long time (like, an hour), so i shut it down using the power button. now i can't get the computer to boot back up. i tried booting without the battery in, i ran the restore disk and went to disk utility and repaired the disk and the disk permissions, and it's still stuck on that stupid gray apple and the little wheel on the white screen. any suggestions?