Why won't my ps3 slim read my uncharted 2

my ps3 slim works fine with all my other games and i take very good care of it but for some reason when ever i want to play my new game uncharted 2 among thieves and i insert the game the ps3 will have that little clock for the please wait thing but then after about 3-4 mintues it frezzes. i checked the disk and there’s no smuge’s or scracthe’s so i thought it was the ps3 so i turned it off from the power botten and that didn’t work so then i unplugged the power cord and waited for about 5-10 minutes and then i plugged it back in and turned it back on and that didn’t work either. i don’t know what to do and even though my dad,bro could help with this they’re too busy my bro has a lot of important college projects and my dad doesn’t get home from work until 10:00 pm ( the time i’m going to bed) someone please help.