On Cisco IOS APs, channel 0 only appears on Factory Default APs. To resolve channel 0 mismatches, bring the radio interface up once and the channel will be set. Once there is a channel set there is no way to return the AP to channel 0 without factory reseting it. This allows you to disable the radio and not get channel mismatches
This value has been seen on firmware versions 12.3(7)JA2 and newer.