I'm only reposting b/c my initial post did not garner a response. If you have any suggestions, or if this post requires additional information, please do not hesitate to reply.
It seems as though my syntax for single_valued_navigation was incorrect. Having taken a closer look at the BNF it seems as though it should have read like this instead:
@ejb:finder signature="java.util.Collection findByLineItemId(java.lang.Integer lineItemId)"
query="SELECT OBJECT(o) FROM Orders o, WHERE o.lineitem.id = ?1"
My problem was that I was thinking in SQL rather than EJB-QL. HTH someone else starting out with EJB-QL!
The problem is you have a comma between the end of the FROM clause and the start of the WHERE clause.
Yes, thanks Dain for correcting my previous post. This was a paste error on my part. In addition to the comma I wasn't specifiying the path correctly for the cmr-field.