Hi all! I used Window Vista and when I first downloaded itunes 10.5 and downloaded the IOS 5 software for my iphone 4, I was not getting an option for Sync with Wi-FI on the computer itunes Summary screen. This is what I done:
1. Re-downloaded itunes 10.5
2. Once the download was completed, I was given an option to either Repair and replace or Erase. I chose repair and replace.
3. Once the installation was complete, I opened itunes from the start menu (not the shortcut).
4. i connected my iphone 4
5. On the summary screen, remember to scroll down. The option for sync with wifi is at the bottom of the summary screen.
6. Click on sync with wi-fi and click Apply at the bottom of the summary screen.
7. Works Perfectly!!!!!
I hope this helps someone!