I googled around a little after I saw the newspost (http://www.cdfreaks.com/news/9484) about Defilerpak 1.17. And apparently there's a newer ffdshow than the ffdshow ver. 05-23-2003 which is stated to be used in the same newspost. If you take a look at this site, http://athos.leffe.dnsalias.com/ , in the changelog, you can see that the application have been updated lots of times since that date.
But another interesting thing is that in that changelog there is no entry for 2003-05-23.
So that brings up the option that this may not be the official ffdshow filter.
You can also find the same file here:
Are these files betas, something else or maybe it isn't the official ffdshow?