Currently, when you press Add Contact in Spark, it presents you a dialog to enter a username of a user. In the same dialog you can also select a nickname and a group for this new contact. When you send this request, a subscription request is shown in another client. After they accept your subscription request you get a subscription request as well. BUT you already filled out the form for this contact when you were just adding this contact. If you don't change the name and the group in this new dialog, you might end up with two copies of the same contact in the end. Spark should automatically presume, that you accept for presence subscription, if you were the one who started this process.