Im using WPA with my iPhone, quite similar device I'd expect the touch to work similarly. What type of WPA are you using? WPA2, WPA enterprise?
It might be a bug with the router and the touch, some slight quirk.
Just purchased a new 32Gb Ipod Touch with version 2.1.1 firmware. The device will not "join" a WPA protected network. Apple tech support acknowledges the issue and suggest that I reduce the security on my wireless to WEP and MAC filtering. That was a supervisor after I spoke to two techs who would not acknowledge the issue and blamed my router. (Dlink DIR-625) All other devices on my wireless work correctly. Asus notebook; Acer Netbook; Xbox 360 with wireless adapter; Wii ; HTC cell phone. Only the Touch will not connect. I have tested and the Touch will connect with either security shut off, or with WEP and MAC filtering (same thing as no security
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