I’m having trouble with the wireless on my 3G iPhone. Either an action works perfectly (for instance downloading e-mail or visiting a website), or it will just time-out. I just jailbroke it and installed sshd. ssh-ing to my it via 3G miraculously works perfectly. However, when connecting to it via WiFi it’ll simply refuse data. That is, until you let the iPhone try to get data itself by for instance visiting a website. Then suddenly the ssh packets come through again. In the background (with screen) I’m running a very frequent ping to my local gateway which makes ssh work perfectly again via WiFi. A very unsatisfying hack.
It seems like an aggressive power safe on the WiFi.