I'm having a similar problem. iTunes automatically finds my iPad (and also tries to find old iPad I no longer have), but does not see my iPhone 4 (nor any old iPhones I no longer have). When I go to Preferences, I can see all current and past devices and dates last synced. my current iPhone 4 shows as last synced Feb 24.
I went to the referenced article and all of the following conditions cited in the article are met:
Whenever the computer and the iOS device are on the same network, the iOS device will appear in iTunes, and you can sync it. The iOS device will sync automatically when all of the following are true:
- The iOS device is plugged in to power
- iTunes is open on the computer
- The iOS device and the computer are on the same Wi-Fi network
my iPhone says (Settings/General/iTunes WiFi Sync) syncing will resume when PC is available. But it doesn't! Also has a button saying sync now, but it isn't activated, entire page is grayed out
iTunes 126.96.36.199 /Windows Vista