Cisco Wireless :: 4404 Wireless Roaming With Old And New APs And WLCs

We have existing AP 1132 with WLC 4404 controller implemented in a site. We started add on new AP 3502 with WLC 5508.Our customer has existing 10 of 4404 controllers and configured in the same mobility group, and the roaming is working fine(ap are 1131).
 
Curently we deployed 2 new 5508 controllers and replaced some 1131 AP to 3500 AP. And the controller created new IP scheme for the wireless client. But after migrate 2 APs, we found that the roaming is not working when the wireless client move from new AP to old AP.
 
When moving from new AP to old AP, the ip address for the client is unchange, but the ping will be droped, and will never come back. Until we do a ipconfig flush, and reconnect, the connection can back to normal, but the ip address als changed to the old IP scheme.