I'll answer my own question:
I "fixed" this problem by adding the oracle jdbc classes to the jar file. great.
but why? the local given db example does not require this????
I have placed oracle libs in default/lib/ext for the datasource and that seems ok.
The local examples come with Hypersonic sQL, which has its lib files built with the jboss distribution, its the hsqldb.jar in the lib dir.