In order for an AP to be detected as a rogue, the following conditions must be present :
-the AP must be 'seen' at least 2 times (through beacons or probes)
-the AP's mac must also be seen on the wired segment
-the AP must be sending beacons or probes
-the AP must be on channel & band that is being monitored.
you may refer to the configuration guide for more information, hope this helps :
http://www.cisco.com/en/US/products/ps6366/products_configuration_guide_chapter09186a00806b0757.html#wp1107407