X360: Jasper Freezing

I posted yesterday that my Jasper 360 freezes in the middle of gameplay on versus computer or on xbl. I played and finished Halo 3 on Easy for 6 hours straight, and my Xbox didn't freeze at all except during the following sequences:

1. Cortana visons
2. Checkpoint saving

Number 2 seems normal because, as with a computer, sometimes the amount of data that hasto be saved and loading is a lot for the cpu to handle, so there's the general pause and waitwhile the system updates everything. Perfectly understandable LAG but something that can be done without.

Number 1 is a bit confusing because of the following: system pauses for a sec while cortana's vision loads on screen. Maybe this would be faster if I had Halo 3 on a HDD, or is this because of the graphics. I heard of games freezing because they are too graphic intensive like NBA Live 09.

Then again 6 hours playing Halo 3 and everything is fine.