Have nobody any idea or a solution for my problem?
It is very important for me to find a soltion in next few days.
You can see the file jboss-service.xml in default/conf.
Somewhere you can find transaction time out = 300 ( 5 minutes) change it !
The outer transaction is still bound by the 5 minute limit. You need either increase the timeout limit or not have an outer transaction and start new inner transactions.