ps3 freezing at xmb

hi all. lately my ps3 has been freezing at the xmb, it also freezes in game sometimes as well.

should i be worried? it is starting to happen more often, also i have it well ventilated and look after it.

anyone had any similar problems?

thanks

omfg my ps3 froze a few weeks ago when i was playin assassins creed, then it wouldnt read any stupid discs (any kind of disc, not just bluray). So now im stuck without a ps3 for a month till i get it fixed, alwell atleast it gives me time to save for unreal 3, but i think if i dont play cod4 soon i will scream :cry: :evil: THERE IS NO EMOTICON FOR WHAT I'M FEELING!