I have had it happen to me twice now that the iPhone is unable to sync with the main database. I just get an error saying there is something wrong with my internet connection, which is bogus. Logging out and back in is the only solution.

I not totally sure what is causing this, but maybe that two devices have changed data and then one syncs back before the other? Just guessing. But if so, having the iPhone sync immediately whenever anything changes would be ideal.