Got it - Sorry, I was looking from the template point of view (since my previous "Start Screen" question had to do with that . . . Now I'm curious myself.
I will take a look and if I see anything related to that, I will comment. Off the top of my head, the "most recent" has to be stored somewhere (INI file or such). It could be that this has gotten changed for some reason.
Try opening some other projects from the "File>Open" dialog (not any of the ones already showing up) and see if the start screen, recent projects gets populated.
Just a suggestion . . .
Syphus's post in Start Screen limiting Recent Projects was marked as the answer