gk and Simon, Thanks for you reply.
After reading my own post again, I noticed I copied the wrong PMF code. I'm using this example (the mix up happened when I changed my code to the code above because I though the "pmfInstance == null"-check could be the problem :D) import javax.jdo.JDOHelper; import javax.jdo.PersistenceManagerFactory; public class PMF { private static PersistenceManagerFactory pmfInstance = null; private PMF() {} public static PersistenceManagerFactory getInstance() { if (pmfInstance == null) { pmfInstance = JDOHelper.getPersistenceManagerFactory("transactions-optional"); } return pmfInstance; } } -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine-java/-/bmaMmcCqMHoJ. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.