From the WLC, if you do the CLI command "sh ap eventlog ", do you see a line that goes like "%LWAPP-5-RLDP: RLDP stopped on slot 0." and then your radios go down/up?
If so, you need to set the AP's to detect whether you are operating in PoE or Injector. Go to Monitors -> All APs -> Choose the AP -> Advanced Tab and under Power Over Ethernet Settings choose Pre-Standard State if you are not using an Injector. If you are, choose Power Injector State -> Installed.