I've called Xbox four times about this now, twice I've done the same thing over, and I was wondering if anyone here could help me.
My Xbox can connect fine to Live, and I can play, search leaderboards, marketplace, etc. But, after a short period of time, I get disconnected from Live (and, to note, I can sign back in the instant it disconnects me). It happens all the time, and when I'm in the middle of Call of Duty it pisses me off, because I lose kills, score, challenges, etc.
I called Xbox the first time, and they told me to make sure my ports were set up. This was done already. The second time, she had me do maintenance to my hard-drive, and that was it. The third time, they had me check my ports again. The fourth time, they had me try (instead of using my wireless connection accessory) plugging directly into my computer, then my laptop, then my router, then my modem. All to no avail.
Help me! :-)