Yesterday I was downloading some "live" augmented diffs (that are now served from a cache, see #342), but got one empty file (2229363.osc). After downloading the same (now, non cached) adiff from http://overpass-api.de/api/augmented_diff?id=2229363, I do actually get some data. Looking around the downloaded files a bit more and comparing them to their currently generated counterparts, I see that most (all?) of them actually don't match up with each other (the current adiffs containing more data then the disk-cached adiffs).

Here's an example: https://gist.github.com/tyrasd/fe213e1d17fc95c3a43b669b1ef154e1