PS Move controller #

Just bought a Move (which is awesome btw) and I'm letting it charge right now.

But can someone explain to me why it is auto-assigned to #7 everytime I turn it on? I only have one other regular controller on (and obivously it is #1).

I only have one dual shock and my Move is assigned #6. I guess it's just a safeguard to avoid mixing it up with any previous controllers a user might currently have synched to the system.