ClobberinTime,
My iPad works just fine for 4 maybe 5 months and one day it just start with this network problem, intermittent service, sometimes the iPad can't find the network or can join the network, sometimes I restart the iPad and the problem was solve for a few minutes and then the problem was back, so I contact AppleCare center thru phone call (the first time) and they said to me, that Apple doesn't recomend using a wireless network with WEP KEY security, that I need to change my router configuration to WPA2 security and if the problem persist I need to call'em back.
At that time my old router doesn't have WPA 2 security, so I change to WPA and the problem was solve like 2 weeks and then it starts again. In order to fix the **** problem, I bought a new router with WPA2 capability but the problem remains, during this time I need to restart my ipad several times per day (only to get Internet connection), I restart the networking configuration like 4 or 5 times and I restart my iPad to factory settings 2 times and nothing, no changes, same annoying problem and the last funny thing my iPad did before I sent it to Apple was, after a normal restart, the iPad doesn't connect like other times, so I check the settings and in the "Wi-Fi" tab it said "No Wi-Fi", I restart the iPad again and the same "No Wi-Fi" I think that was the end of my iPad.
So I call AppleCare center, explain all of this problems and what I did, change to WPA, change my router, configure WPA2, restart my iPad, restar networking setting, restart my iPad to factory settings, except the "No Wi-Fi" thing because that problem pop-up when I already call them, and told them the problem remains, so this guy tell me, that I did all the possible solutions for this problem and the next step is send me a box to pick up my iPad for inspection and repair. I already send my iPad now I'm waiting for any news from them.