Unallowed characters in concept names

Hi,

My question is straightforward, but I didn't find it through Google. Actually, I ran into someone with the same problem, but there was no answer in the thread.

How should I escape things like the parenthesis in:
	PREFIX dbpedia: <http://dbpedia.org/resource/>
	SELECT ?p ?o
	WHERE { dbpedia:Orange_(fruit) ?p ?o . }

(Gives error about "(" )

Note that the following does work:
	SELECT ?p ?o
	WHERE { <http://dbpedia.org/resource/Orange_(fruit)> ?p ?o . }

Thanks,

Arjon Buikstra

P.S. Thanks for the comments on my Union question, it really helped to clarify the problem!