I just posted about this same thing happening to me today! Initially, we could not get my Keen sandal off the cleat (also Eggbeaters Candies), and my DH had no luck messing with it with a couple of tools. I just kept turning it around and pulling, and suddenly it gave way. I only unclip on the right, so was very glad I didn't have to put my foot back in that sandal and ride that way (or go home, even worse, we were only 2 miles into a 45 miler).
Good luck! That's the last time I tighten my cleat screws myself...DH does a much better job.
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow