I'm very sorry to hear you experienced problems updating your itinerary. The best way we can help in a situation like this is knowing what page you saw the error on, what the error said, when it happened and what browser you were using. If we have this information we have a much better chance of fixing the issue. You can leave this information in our help form: https://www.tripit.com/uhp/feedback

For the itinerary page, we're still working on some additional enhancements based on the feedback we're hearing. Again, we sincerely appreciate how much our users care about the product and we follow all your comments very closely.