The first time I tried it, 'Attach' did exactly what it was supposed to and gave me the list of games in the edit option. I changed a Mode setting just for the heck of it. The next time I opened the app and tried Attach is when the shutdowns started.
I booted HDL, and only the game I'd edited was listed. After cleaning my pants, I crossed my fingers that WinHIIP's repair option would fix things. It looks like things are back to normal, but I'm not sure how soon I'm going to give this another shot.