I just tried the 5.4 version by doing the following:
Undeployed the drools-guvnor.war that was running on jboss
Added the guvnor-5.4.0-SNAPSHOT-jboss-as-7.0.war to the deployment folder and restarted the server.
Created a new BPMN2.0 model, added a start and end event with a task in the midle and saved...the designer refreshed and all the process information was lost...a message in the lower left corner of the designer left pallet said "unable to retrieve process information".
The guvnorEditorObject is now correct but I didn't try the register method because the save isn't working. I assume that there were changings in the rest communication with the repository which made the designer unable to save.
Also noticed that .css error were corrected :) ....many thanks for the help and time.
If more information about the 5.4 deployment is necessary please do tell.
Thanks again