What speed of connection do you have, and what average pings??
I think that you can drop out of games fairly regularly if you're lagged too much...Sometimes happens to me on my ADSL 512K, for some reason it starts to lag pretty bad. Usually only 1-2 days a month.
As for the freezing, I also had the same problem... Until I bought a new shelving system for my a/v gear, and it hasn't frozen since (once I got the 3 rings of death!). I realised sitting directly on top of the amp was about as dumbassed a move as you can make!!!
Anyways, just saying maybe your box isn't getting good ventilation and is overheating.