As far as i can see the part of the bpmn from eclipse with the script
i.e.
<extensionElements>
<tns:onEntry-script>
<script>System.out.println("test");</script>
</tns:onEntry-script>
</extensionElements>
will work if script tags contain namespace prefix i.e.
<extensionElements>
<tns:onEntry-script>
<tns:script>System.out.println("test");</tns:script>
</tns:onEntry-script>
</extensionElements>