***Edit***
At last, after approximatively  one month i can run tomcat 5.0.30, sun java 1.5.06 and xwiki
 without a big tomcat crash.
But i still got error from java socket the error message is:

** BEGIN NESTED EXCEPTION ** 



java.security.AccessControlException
MESSAGE: access denied (java.net.SocketPermission localhost resolve)

I think it's a ".java.policy" file settings error, how can i set this policy with sun java "policytool"

Please help me before i get mad.