OPENJPA-2491.  Variation of the patch as provided by Romain Manni-Bucau.  Besides clearing the cache, I also corrected the spelling of "parameter" in this testcase name and another related testcase.

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@1588977 13f79535-47bb-0310-9956-ffa450edef68