Since a few days, the sync feature is not working anymore. This seems to be due to a behavioral change of the Microsoft SkyDrive cloud service.
I am working with high pressure to tolve the issue, and publish an update as soon as I have a working solution. Until then, please be aware of the current behavior:
If one of your devices performs a sync, and there are local changes on that device since the last (unsuccessfull sync), the app will still upload and replace the file on SkyDrive.
But all devices, when trying to sync, will not be able to download that file (actually the download succeeds but the result is an empty stream, therefore there is no error message shown to the user), so that every device will remain with it’s local version of the list.
Please apologise for this inconvenience, I will provide a fix as soon as possible.