Weird network issues

Something really messed up has been going on with my Xbox lately. My Xbox is set up to a router about 15 feet from it, and says that it usually has four bars. However, whenever I enter an online match on ANY game, the same thing always happens: I play for 5-10 minutes with no lag, and then my screen spazzes out and (A) I lag out, or (B) my Xbox freezes. Then, when I go back to check my connection, I still have four bars! I really don't know what to do, and I'm guessing that it means my Xbox is on the way out, but I've had no problems offline. Does anyone have any suggestions?

Well, you can try and contact Microsft about this or bring it back to the store you bought it from (if you still of the warranty on it). Other than that, there's nothing else I can really do...