okay... so err.
That's a bad idea.
Seems like it managed to mount the wrong /var/local by doing the nasty shutdown
and then decided to hard reset the device!
HEH. word to the wise. don't do that
EDIT: KUDOS TO IXTAB:
I ran the Collections manager, it noticed the missing cert, fixed it. ran JBPatch, installed mods, my customised store button even came back.
Now that's service.