Thanks so much for trying out my test case. I'm glad that you had different results: it gives me hope for improving things on my end.
The version of ParserFunctions we use is from http://meta.wikimedia.org/wiki/ParserFunctions, which is pointed to by the "table of functions" on http://www.mediawiki.org/wiki/Parserfunctions.
Looking around some more, I now see http://www.mediawiki.org/wiki/Extension:ParserFunctions, which appears to be much newer. I will install that and see if the problem goes away.
Thanks again. DanB
-----Original Message----- Possibility 2:
* You're running an old version of ParserFunctions which doesn't know how to plug in to the new parser preprocessor.