I've noticed over the past few months that the updater frequently can't complete downloads, and hangs somewhere around 2-16kB short of completing the file transfer.
For instance, the past few days, the updater has been telling me a new version of PeaZip Portable is available, yet the updater consistently stops making any progress at 7136/7139 kB.
Since the problem is usually repeatable (it occurs 100% of the time when attempting to update this specific app), it leads me to wonder whether the updater should have any means of reporting download issues in order to correct problems on the server side.