it's more worse than that. they wont accept your PS3 eventho you willing to give them RM 1 million for repair

You should understand this: Sony Malaysia DOES AND WILL NOT entertain any PS3s consoles not being a MY set.
Which also means, they won't even care if you pay them, they'll not look at your unit unless it is a MY set. Its under their T&C warranty.

I suggest you do this, play PES 2008 again and play a full match if possible. If there are no problems then the problem may just be the COD4 disc being faulty.
When a Blu-Ray disc is faulty, it can automatically jack the Blu-Ray laser in your PS3 to go too close onto the disc because its having difficulties reading data off from it and thus freezing the game.

Try other games as well.
A dying lens symptom is frequent freezing(which means just freeze out of no where).