Too bad this plugin isn't being maintained by the author. It only works with GIMP 2.4 from what I'm reading. This tool should be adopted as a first class GIMP tool.
What's the error that you're getting when you try to run it? Are you using the patched file from my tutorial?
http://www.logarithmic.net/pfh/resynthesizer.
(I forgot where I read about the "since 2.4" part.)