Hi Gavin first, as I said before, I learn this from a ducument about Ejb and Jsf in german language and they connected to MySql with Hsqldb dialect, and I said it is strange but only after that it worked. However, my configuration is exactly correct but it doesnt work with MySql dialect so maybe it is a bug in the Seam. now I am at home and can not show you the link that refers to that document. second, I didnt say that all people go and change their dialect as I change it, I just wanted they know I passed these works to resolve my problem, maybe some one who know more, could find the exact reason of this weird problem and reply to this thread. if only, you had said your idea about this and had said why this happen. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3980234#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...