I am sharing the wifi connection from my MBP to my desktop since I haven't run a wire or set up wireless yet. It works, but every minute or two the Limited or No Connectivity icon appears, and for a few seconds, the desktop is offline. After a few seconds, it works again. This has happened with the desktop running both XP and Linux, so I don't think it's an OS issue. The wifi connection on my MBP is rock solid, and it always works just fine whether or not the desktop can connect. What could be causing this?