This is an odd one, and I've been unable to find any info on it.
Basically, all of my admin pages seem to load a cached version first - a refresh is needed to show the actual current state. For instance, "All Posts" will show only the first few I ever added, until I reload.
But it's especially annoying on any "Add New" page, because it will attempt to overwrite the last post or page I published. I first noticed this after the first auto-save: The generated permalink was the same as the previous post I'd made. Sure enough, when I went ahead and published the post (even after editing the permalink to make it unique), it REPLACED the prior post.
If I let it autosave, then reload the page, it works fine.
So far I've tried disabling all profiles, switching themes, and re-installing WordPress. This problem remained. Does anyone have any suggestions of what might cause this? Even just a point in the right direction will be greatly appreciated.