So here is my situation... Bought iMAc with preinstalled Lion on it. But as I don't won't Lion yet, I formatted disk so it is empty now. But the system won't boot from my SL DVD. It stucks on Apple logo. I hear DVD is spinning but then just stops and screen remains there. DVD is ok as it works in my other iMac. Also System would boot with windows install DVD. I noticed the same problem with booting from DVD in OSX even before I touched my OSX system, but I was thinking it is because of older version of OSX then the one installed. Same thing happens if I try to boot from USB device. Any help? Thanks!