My iPod Touch 32GB connects via my D-Link router and works just fine when it is connected. However, after leaving and using it on a different network somewhere, it no longer automatically connects when I return to my office. It used to manage this, but stopped a few months ago. If I restart the router (unplug it, wait, replug it), the iPod can connect -- but that isn't a very useful solution. I assume this may be related to a "Wi-Fi Network" setting but I'm not sure where to look.
The network has 2 desktop Win7 machines via Ethernet; 1 laptop via Ethernet; 1 wi-fi printer -- and is fully accessible when friends come over with other wireless devices (iPhones, Android, laptops, etc.).