What version of Anim8or do you use? I couldn't reproduce your problem... The script will only work fine on v0.97c or later and it won't load if you're using an older version... (well, it will load on v0.97b, but it may not work correctly).
Anyway, I tried to dive into the code to find a possible bug and I fixed several details, but I couldn't find anything that would cause the script to fail. This was one of the first scripts I have written and if I made it now, it would be much shorter and less messy. I'm thinking of rewriting it from scratch if the problems keep on appearing...
Here's new version of the script, let me know how it works.