Question of freezing on PS3 (160gig)

I was playing Call of Duty 4 Modern Warfare 2, trying to join a game online but for some reason the menu froze. everything was moving on the screen like the stars for upcoming players, the bar on the bottom, but for some reason i couldn't navigate for some reason. And right after i had pressed the PS button to try to quit out of the game, it took maybe 10-15 seconds with "Please Wait" on the screen. After that it beeped 3 times i believe and returned back to the playstation desktop. Well, my question is, Is it the game or console and should i be concerned? And could it be that the disc is smudged or damaged even though it looks normal? Thanks.

Something similar happened to me yesterday. It froze on the MP lobby. Had to reset it by pressing the touchpad thingy.

Does anyone happen to know how this happened? whether it's the game or not?

No need to be alarmed, it happens.

Clean the disc with window cleaner. Now ya know.