Problem checkrad cisco ap1200

[ph b.]

Hello,

The script "checkrad" not run with my ap1200, when i test it i have :

SNMP Error:
Received SNMP response with error code
  error status: noSuchName
  index 1 (OID: 1.3.6.1.4.1.9.2.9.2.1.18.XXX)
SNMPv1_Session (remote host: "192.XXX.XXX.XXX" [192.XXX.XXX.XXX].161)
                                community: "public"
                                 request ID: -662891836
                              PDU bufsize: 8000 bytes
                                      timeout: 2s
                                      retries : 5
                                     backoff: 1)
  at /usr/sbin/checkrad line 221
checkrad: No SNMP answer from cisco
checkrad: not found!

I think it is a problem with the ap but i don't see what it is.
The conf for the snmp on the ap is :

access-list 111 permit tcp any any neq telnet
snmp-server view dot11view ieee802dot11 included
snmp-server community public view dot11view RO

If i erase the view, i have the same problem.

Furthermore, when i use the tool snmpge for the oid 
1.3.6.1.4.1.9.2.9.2.1.18.XXX, it return me the same result : noSuchName.

The ap use the IOS 12.3(2)

And when i connect on the ap and do "show aaa user all", i can see the users 
name et other data. So the logins are stored on the ap but can i get them by 
SNMP or not ? how can i fnd the good OID ?

Could you help me ?

thanks

ph