Spurious reports of InvalidPropertyURIException on seemingly good URIs...

Using C-SPARQL 0.9.1 with Jena v 2.11.1 (I think).

In this case it’s reporting <http://www.sp.ibm.com/km/ont/km4sp#observationType> as a bad property URI. It’s also reported <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>.
The confusing bit is that the same properties (apparently the same) are processed fine earlier than this report

[ERROR] StatementResultServiceImpl - Unexpected exception invoking listener update method on listener class 'QueryListener' : InvalidPropertyURIException : <http://www.sp.ibm.com/km/ont/km4sp#observationType> <com.hp.hpl.jena.shared.InvalidPropertyURIException: <http://www.sp.ibm.com/km/ont/km4sp#observationType>>com.hp.hpl.jena.shared.InvalidPropertyURIException: <http://www.sp.ibm.com/km/ont/km4sp#observationType>
at com.hp.hpl.jena.rdf.model.impl.PropertyImpl.checkLocalName(PropertyImpl.java:67)
at com.hp.hpl.jena.rdf.model.impl.PropertyImpl.<init>(PropertyImpl.java:56)
at eu.larkc.csparql.sparql.jena.JenaEngine.addStatement(JenaEngine.java:126)
at eu.larkc.csparql.core.engine.CsparqlEngineImpl.update(CsparqlEngineImpl.java:283)
at eu.larkc.csparql.core.engine.CsparqlEngineImpl.update(CsparqlEngineImpl.java:48)

Any ideas?

BTW, I’m using the C-SPARQL ReadyToGoPack, which is a packaging of the jars and a few extras. I’ve had difficulties in the past in source-level debugging of C-SPARQL.

Thanks,

Mark