I got it too - comes when you press "output" after the composit.
That particular IM is run by net4tv - so I'll contact them about the problem.
Here are the other IM's available -
Arbor - http://studio.webbyland.com/MagickStudi ... Studio.cgi
Koyaa Redux - http://koyaanisqatsi.imagemagick.org/Ma ... Studio.cgi
Redux - http://redux.imagemagick.org/MagickStud ... Studio.cgi
Amish - having trouble getting this to open