Invalid conversion from type class java.lang.Object with value 'oracle.sql.ROWID@1379cbd' to type class java.lang.String

I have a VDB with 3 queries that select direct from an Oracle table, where a SUBSTRING function is being used on the ROWID column.

I can successfully SELECT from the 3 queries without error, but when selecting from a 4th view that is join 2 of the 3 tables that I can successfully SELECT from via SQL SquirreL, the 4th view query is failing with;

2011-03-31 11:35:14,968 DEBUG [org.teiid.PROCESSOR] (Worker0_QueryProcessorQueue2) [Ljava.lang.Object;@168fb5a
[TransformationException]Invalid conversion from type class java.lang.Object with value 'oracle.sql.ROWID@1379cbd' to type class java.lang.String
at org.teiid.core.types.basic.ObjectToAnyTransform.transformDirect(ObjectToAnyTransform.java:59)
at org.teiid.core.types.Transform.transform(Transform.java:47)
at org.teiid.core.types.DataTypeManager.transformValue(DataTypeManager.java:781)
at org.teiid.dqp.internal.process.DataTierTupleSource.correctTypes(DataTierTupleSource.java:155)
at org.teiid.dqp.internal.process.DataTierTupleSource.nextTuple(DataTierTupleSource.java:227)
at org.teiid.query.processor.relational.AccessNode.nextBatchDirect(AccessNode.java:154)
at org.teiid.query.processor.relational.RelationalNode.nextBatch(RelationalNode.java:274)
at org.teiid.query.processor.BatchIterator.finalRow(BatchIterator.java:70)
at org.teiid.common.buffer.AbstractTupleSource.getCurrentTuple(AbstractTupleSource.java:69)
at org.teiid.query.processor.BatchIterator.getCurrentTuple(BatchIterator.java:82)
at org.teiid.common.buffer.AbstractTupleSource.hasNext(AbstractTupleSource.java:91)
at org.teiid.query.processor.relational.MergeJoinStrategy.process(MergeJoinStrategy.java:158)
at org.teiid.query.processor.relational.JoinNode.nextBatchDirect(JoinNode.java:196)
at org.teiid.query.processor.relational.RelationalNode.nextBatch(RelationalNode.java:274)
at org.teiid.query.processor.relational.ProjectNode.nextBatchDirect(ProjectNode.java:162)
at org.teiid.query.processor.relational.RelationalNode.nextBatch(RelationalNode.java:274)
at org.teiid.query.processor.relational.RelationalPlan.nextBatch(RelationalPlan.java:161)
at org.teiid.query.processor.QueryProcessor.nextBatchDirect(QueryProcessor.java:150)
at org.teiid.query.processor.QueryProcessor.nextBatch(QueryProcessor.java:105)
at org.teiid.query.processor.BatchCollector.collectTuples(BatchCollector.java:115)
at org.teiid.dqp.internal.process.RequestWorkItem.processMore(RequestWorkItem.java:250)
at org.teiid.dqp.internal.process.RequestWorkItem.process(RequestWorkItem.java:184)
at org.teiid.dqp.internal.process.AbstractWorkItem.run(AbstractWorkItem.java:49)
at org.teiid.dqp.internal.process.DQPWorkContext.runInContext(DQPWorkContext.java:188)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$RunnableWrapper.run(ThreadReuseExecutor.java:116)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$3.run(ThreadReuseExecutor.java:290)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)