TopLink Essentials by default uses 2nd level cache that is not being updated when you manually (not via the same EMF as the one you used to run your 1st test) change the data in the database.
You either need to cleanup data via EM apis, or refresh your data explicitly in the 2nd test, or disable the cache.
regards,
-marina
[Message sent by forum member 'mvatkina' (mvatkina)]
http://forums.java.net/jive/thread.jspa?messageID=216247