Thanks for the reply.
Yes, I understand the access is controlled by group membership, I have 2 groups setup and I've integrated them into Openfire by selecting them in "Users/Groups, Groups, Group Summary" menu, the users who's AD accounts are in the groups are happily signing into Spark.
My question is how would I go about removing these groups if required that I previously selected from the "Group Summary" menu .. do you need to delete in AD..seems a bit odd that after selecting them in OF theres not a menu to show those previously selected?