Yes, of coz I've started with this...making the groupcategory in GJ, and a forum top category in Kunena. I have setup the integration ig GJ to yes and added the forum topcategory ID, saved...
Went to frontend to make a group in GJ with a user...in the group profile nothing about a forum thing appeared..so this integration seems to be totaly dead...not functional... or there must be some trick to makes it alive...