Comment 5 for bug 876627

Not sure if this is related, if someone could let me know if need to open another bug.

After using a second screen, I have one persistent (extra, over and above the normal behaviour) desktop that will not "close" or cannot be removed.

I.e. so if I was only using one desktop, there would be the default additional "spare", but also this additional desktop that is only present after using a dual screen set-up and returning to single default screen (laptop).