Similar problem but it may be due to the Android ToDo Today app (listed in TD's 3rd party app page). I have the iOS TD app running on an iPhone 4 and an iPad 2 and haven't seen any sync errors with the server. I have ToDo Today on a Samsung Galaxy Tab 3 which I hadn't opened in about two weeks. But when I did - wham! - two weeks of updates down the drain. Looks like ToDo Today erroneously sync'd the old data to the server instead of downloading the newer data. That's a fatal flaw - the ToDo Today installation is now history.
Android version of ToodleDo coming soon...? Please?