Sadly Steam causes numerous little bugs that go unnoticed, and a dozen or more major ones that result in lost saves and achievements being lost as well. That is why Gaslamp added their own method of tracking achievements. But think of it as a beta. It doses not and cannot currently track every possible error and/or bug that Steam causes. But I expect it will get better with time to the point that people never see this thread. And the "Steam Cloud" stuff happens even if you only use a single system too. One day, I expect you will be able to play without Steam even installed and get achievements that could be unlocked in mass when you install Steam. That day is not today in some cases though. If you check my Steam statistics and achievements you would think I am a newblet who has never even played the game. But I have done almost everything. And the hours I have played... Well it would exceed the maximum message length to put that many digits in a post.