You may still continue to see the "DUPLICATE IP WITH DIFFERENT MAC DETECTED" alarm if the below situation arises in your environment:
Let's assume AP 'A' with IP Address x.x.x.x and AP 'B' with IP Address y.y.y.y are down:
If AP 'A' goes online and is assigned the IP Address of AP 'B' which is y.y.y.y although AP 'B' is still offline, you would first see for the AP 'B' the alarm "DEVICE HAS STOPPED RESPONDING TO POLLS" followed by the alarm "DUPLICATE IP WITH DIFFERENT MAC DETECTED"
The "DUPLICATE IP WITH DIFFERENT MAC DETECTED" should get auto-cleared when the AP 'B' eventually goes online provided with an IP Address other than y.y.y.y
The above issue could be avoided via Network Administrator by:
1) Adding more dynamic IPs to the IP pool (or)
2) Adding more dynamic IP retention time for the end devices