iTunes won't recognize my iPhone 3GS and will not show under icon under My Computer

After syncing my daughter's first generation iPod with my iTunes, iTunes no longer recognizes my iPhone 3GS and the phone does not appear in My Computer. iTunes still recognizes my iPad, though and the iPod. How do I get iTunes to recognize my iPhone 3GS again? Under the general settings of my phone, the itunes Wi-Fi Sync says sync will resume when "OWNER" is available.