iPad Progress Report
Now that the 300,000 early adopters have had a few days to play and work with their iPads, we're moving beyond the "first impressions" articles (but here's a video of a 2-1/2-year-old's first encounter with the device). The detailed reviews aren't out yet. The largest source of early complaints is a complex of problems with Wi-Fi reception. Apple has posted a technical support note implicitly acknowledging the problems and suggesting some work-arounds — specifically, changing SSIDs or encryption methods on base stations that offer both 2.4-GHz and 5.8-GHz signals. Finally, here's a detailed look at the gratuitous pain Apple imposes on those desiring to get iWork files transferred from and to the iPad.
From your link Apple suggests:
1. update your router's firmware
2. change your router's location
3. set your router to operate on one 802.11 standard
4. change your router's security
5. rename your networks
In the reported cases only the newly released iPad is having problems, but according to Apple the problem is with your router.
At the very least, step 1 is not so absurd.
A while back, the girlfriend bought a Macbook, which was the first Apple device that ever tried to connect to my router over WiFi. Even 6" away from the router, the Macbook would not connect; any PC we tried would work all (15 feet) across the apartment.
I was prepared to chalk it up to shoddy Apple networking hardware, but on a whim tried a firmware upgrade. Lo and behold, after the router rebooted the Macbook immediately recognized it and connected without issue.
I have no idea what/where the actually problem was, but if Apple had suggested the exact same list of steps to me they would've been right on the money.