This was actually driving me crazy to the point where I had to plug a cable in here at my desk… WiFi is definitely finicky regardless of position relative to my Airport when my Macs have no issue at any time.
Here are the symptoms of the problem: A Wi-Fi-enabled computer running Windows XP is working fine one minute, pulling up Web pages and processing e-mail. Then, for no reason, the connection drops, websites fail to come up and the e-mail flow stops. The small wireless connection icon in the taskbar says the signal from the access point is strong, so the problem isn’t that the user wandered out of radio range. The icon even shows that the computer’s Wi-Fi hardware is sending information to the access point — it’s just not getting anything back. And manual attempts to re-establish the connection through XP’s built-in wireless configuration tool won’t do the trick. Even more bizarre, the connection sometimes comes back on its own. [Wired News]