Well this reverse order bug popped up again today. But, I think I know how to fix it.

I was having a problem with my feed being updated as well, so I decided 'what the heck', why don't I just republish the entire blog.

That seemed to do the trick. All of my posts are now back in the correct order and it solved the feed problem too.

This is probably just like compacting your folders in Outlook. Somewhere in the system, after you draft a bunch of stuff then publish them out of sequence – things get a little askew. By republishing your entire blog, it just 'reorders' everything.