With the recent release of iTunes 7, lots of folks are upgrading and finding that their iPods are no longer recognized. This is actually a common problem, and not isolated to iTunes 7. Sometimes it just happens, even without upgrade. I found my iPod nano was no longer being recognized by iTunes after upgrade, but fortunately, the fix is pretty simple.
First, some details. After upgrading, I plugged in my iPod nano, and heard it detect the hardware. However, it never showed up in iTunes. I opened up My Computer, and found that the drive was being recognized, so Windows was acknowledging its presence. iTunes just no longer was recognizing its existence. I unplugged it and re-plugged it in, but it just wouldn’t pick up.
Apple recommends the five Rs when you’re having troubles: reset your iPod settings, retry on a different port, restart your computer (after updating software), re-install your iTunes software, and restore your iPod (erasing all data on it). Trying each of these steps (one at a time, not all of them) will solve most problems with iPods.
In my case, I first reset my iPod settings by scrolling to Settings->Reset All Settings (on the iPod itself, silly). Once I did this and my iPod rebooted, it was recognized by iTunes. Yay! However, the firmware was out of date, and iTunes requested I update to the latest. (Note: the old iPod updaters appear to no longer work — you now appear to have to use iTunes to do firmware updates.) Unfortunately, the update didn’t work. Here’s a tip: wait until your iPod finishes syncing. Once finished, I did a restore + update, to get it to the newest firmware. Once that was done, my iPod re-picked up, and I had to configure its sync settings anew, and leave it to copy music.