The same thing happened to Blissymbols[1], as documented by radiolab[2].
This has also happened with the language Lojban[1], which was 'forked' from Loglan[2] when the creator starting making copyright complaints so the community could maintain control.
Such an odd concept that someone could 'own' a language, but I guess if you created it I can see why you would want to.
[1] http://en.wikipedia.org/wiki/Lojban [2] http://en.wikipedia.org/wiki/Loglan
I seem to remember Umberto Eco mentioning that he does not offer his own interpretations of his novels for a similar reason, but I can't find the quote.
The Search for the Perfect Language - Umberto Eco - 2010