Cappuccino nib2cib Failure

If like me you get this error from nib2cib when working on a NibApplication in Cappuccino:

js: "/usr/local/share/objj/narwhal/packages/objj/lib/objj/objj.js#20(eval)#2410(eval)", line 78: uncaught JavaScript runtime exception: TypeError: Cannot read property "origin" from null

Then chances are that you've included a control that's not supported. Here's the list of controls you can use (see the Class in the Identity Inspector in Interface Builder).