moulidharan ,
Sorry that you are seeing this issue with MyEclipse.
Can you answer some more questions for me to understand the issue better ?
1) Can you share your Build Id from Help > About MyEclipse Enterprise Edition > Build Id ?
2) Can you recheck your persistence provider given in the <provider> tag in the persistence.xml ?
3) Also take a look at this thread which discusses the same issue :
http://www.myeclipseide.com/PNphpBB2-viewtopic-t-17323-sid-08e82e38591eab877e20737ad0e1fc5a.html
4) Also send us your persistence.xml for further investigation.
Let me know how this works for you.