ps3 freezing need advice :)

Well this is a wierd one, it freezes all together, not being able to go to the dashboard or w/e you call it on the ps3, no sound, no nothing. Just completely freezes. But heres the weird part, it only happens every now and then and not a constant 15 minutes or anything. I mean I can play Infamous for 6 hours one day, then pop in uncharted the next day and it freezes completely in about an hour. But its not just one game it has happened at one point in time with all my game. If anyone has anyways of fixing this please tell me. I would like my last resort to be getting a slim ps3, oh also its a 40gb ps3.

Nope no 3.0, its the one before the 3.0 update.

Herm.. I dun think getting a slim PS3 is the right way to solve this problem...

To the people saying getting a slim ps3 wont fix the issue. Yes it will if I cannot fix the system and it progresses to getting worse. I don't know what all the hate on the ps3 slim is about but get over it please. Like I said that was my LAST resort. And also thanks to all who have responded with helpful posts :)