Liquify twirl stopped working in CS6

As you can see in the attached image, the Twirl Clockwise Tool has stopped working for me in CS6 and instead distorts the image in an unusual way (I held the cursor down in 5 spots, from right to left, with increasing duration). It even rips a hole in the image. Maybe it is creating a wormhole through another dimension? Who knows, but it is not what I want! I have tried twiddling all the knobs but nothing fixes it. What can I do? It used to work on my current install. Has anyone else had this problem?