Suddenly can't sync phone, says I need more space?

[rockinrocker]

I went to try and sync my phone last night, and I can't because of this:



Screen Shot 2012-05-25 at 11.19.29 AM by davidaltemeier, on Flickr


I haven't added anything (let alone 20+ gigs of stuff), sync new apps is NOT checked.....

Any ideas?

Thanks