Dwr 2.0 and spring session scoped bean not working with url rewriting

I have a web page that uses dwr 2.0 for ajax calls in combination url rewriting. The problem is that on the first visit to the page in question the dwr calls doesn't work. The dwr call returns:

dwr.engine._remoteHandleException('0','0',{javaClassName:"java.lang.Throwable",message:"Error"});

and the server log reads:

WARN DefaultRemoter : Method execution failed:
java.lang.NullPointerException

The request being sent contains:
scriptSessionId=8278AC24F318F42723FB37087B78AA6D606

still somehow the remote method invokation fails. This might might have somesthing to do with trying to access a spring session scoped bean through dwr?Start Free Trial