My first guess is that others were right, something is plugging the drain on the drip pan.  I'm far from an expert at this, just relaying what I've been told.

I bought a used pop machine several years ago, and found there was a sponge in the drip pan.  I wondered about why it was there for a while, then decided it was to soak up any extra water in the pan so it wouldn't run over.  I don't know if my theory was right, but perhaps that idea might work in your case? 

If it is leaking water at a regular interval, and not doing that before, you might have a problem with freon levels?

Disclaimer:  I know nothing (Just like Sargent Schultz on Hogan's Heros from TV in a previous life), but am willing to toss out ideas for your consideration.

I hope you get this problem figured out soon, it is not good to have a mess in the house on a regular interval.