Milestones, that's what I thought I was doing!
So for example, I create
1.0 Rough Mix
1.1 Drums finished
1.2 vox fx
1.3 starting automation
Let's say I mixed it down. Decided I don't like it and want to go back to an older version. The 'snapshot' I thought I created: e.g. 1.2 vox fx isn't the version I first saved, but the version created when I hit control S right before I saved 1.3. That is: all the changes between saving 1.2 initially and creating 1.3. So there's no way to get back to the milestone of 1.2.
I guess I'm thinking I need to get into the habit of saving the milestone version. And then immediately create the next version and work into that one.
It's frustrating because it took me so long to realize that I don't have the save points I thought I was being so careful to create all this time.
Save As, may be the better way to go. That way I can be pretty sure that the end point of the previous version is the place I want to go back to when necessary. But then, I need to Save As again before I start editing that file! Yikes.