PS3 says "This Disc is Invalid 80029906"

[CarolinaBlu]

I was watching Lost Season 4 Disc 2 last night with the old lady and all of a sudden it freezes up! I tried ejecting the disc and it took so long that I actually manually shut off the power and powered back on. I popped back in, saying "Huh! That's weird...". The disc freezes in a different spot, but I can eject it with my remote this time. "Ok, lets try this once more...". Now it won't even recognize the disc or when it does, it gives me an invalid disc error message! Whattya mean invalid disc?!?! So I pop in some other blu's which play fine but take forever to pop up on the menu... then I pop in another disc from the Lost set and it is only recognized after like every other time. What is the deal? Is my PS3 the issue or is it these Lost blu's? What should I do???