iTunes wireless sync works for iPhone, not iPad

[Flake]

this is annoying the ***** out of me and I can't for my life figure out why it's happening. everything works fine for my iPhone 4, but my iPad 2 just refuses to show up on the iTunes sidebar unless I plug it in with a cable first. otherwise I can't get it to wirelessly sync

 

[saving107]

I had a similar issue and the trick that worked for me was to

1. Plug my iOS device to iTunes
2. Uncheck the "Wireless Sync" box
3. Hit sync
4. Now check that box
5. Sync

 

[SplicedBanjo]

I had the same problem with an iPad 1, but it eventually just resolved itself somehow. I wish I had a more specific solution to offer, but a good start would be to make sure you have the very latest updates to iTunes and iOS.