It looks like you have some clients that are getting more than one IP address. We have seen this happen on Androids because they sometimes manage to accidentally run more than one dhcpclient instance on their WiFi adaptor. Because of the way they behave, when they get this way they start getting addresses, abandoning them, and then getting new addresses pretty frequently. Likely if you look at your core router's ARP table for these MAC addresses they will have several more IPs associated than what you see on the controllers. There may be an additional problem with exactly how the controller is handling this situation, but the root of the problem is client-side and there is a solution on the server side. You have two options:
1) If you can get your production DHCP servers to verson 4.3 (assuming they are isc-dhcpd) then you can apply the ignore-client-uids option to prevent two clients on the same machine from being assigned different addresses. Most networks do not need to allow this to happen, and it can also help in general with the seperate clients run by bootp/boostrap/os.
2) If you have to wait for 4.3 to make it into your approved distros, then you can periodically put static lease reservations for the clients you find with more than one IP address in Airwave. The easiest way I found to do this is to build a view that show you just the MAC and IP fields in Airwave and then you can cut and paste that into a script to generate stanzas. You don't have to get all of them just most of them to keep the amount of this activity low.