sync issues with itunes

When I try and sync my iphone to itunes, which i have to do every once in awhile because it starts to work funny (ie: sending duplicate texts from an earlier conversation, internet not working properly). But, when I plug in my phone to my computer, I can see my iphone in itunes, but when I try and sync it I get a message that says it "could not be synced because the sync session failed to start." That's the first time I've ever received this message.