[Solved] Hitting space bar prompts project to be saved?

I just started a new project in X3e, and all was going smoothly until yesterday.  I don't know what I did, but I noticed that hitting the space bar to stop play caused the project to display the asterisk (*) showing that I had made a change to the project, even though I had done nothing but hit stop (space bar).  When I started the session, this was not happening, and it even happens when I play the song from beginning to end, and it returns to zero automatically at the end.  This is happening even though I make no changes during playback.  How did I change the behavior of the space bar without my knowing?  And, why would it prompt a save just playing from the beginning to the end?  I thank you all in advance if you have any advice.

It's a specific project, and a new one started in X3.  It was playing fine when I started the session.  It would play from beginning to end without showing a change (*) in the project header.  It would behave normally when I hit the space bar to stop play.  Then, somewhere along the way, I noticed that hitting the space bar would make the asterisk appear.  I don't know what I did to make the behavior change in the project.

Do you have auto save activated? I have no idea what could cause that behavior but I personally would revert to manual saves to avoid getting nailed down to changes I didn't want... although I guess you could go back through the save history if need be but that's a pain.
 
Have you checked your Preferences to see if anything weird got bound to your Spacebar somehow? Do you maybe have a sticky mouse button that is changing parameters without you knowing or a MIDI controller doing something weird?
 
Cheers.