GX1 inexplicably taking two exposures with one shutter press.

I've been using my Lumix GX1 for about 6 months now, and for the most part it's worked pretty reliably. However, in the past month or two, it has developed a new habit where it randomly takes two exposures with one shutter press. I'm assuming I turned on some setting or feature on accident, but I've scoured the documentation and looked through the menus and it just doesn't make any sense. Sometimes it does it two, three times in a row. Sometimes it takes single exposures for a while. There is no pattern, and no lighting conditions seem to affect it. It is as random as I can tell.

And, it is SUPER frustrating. Any help will be greatly appreciated!