I don't know why you're getting 2 MAC addresses.
Because of some weird issue in the firmware?
Given they're sequential, they are likely from the same device.
That has to be the case.
What does Packet Capture show.
I have not captured any packets so far, but I will.
One thought, do you have a static mapping configured for that address, but with the wrong MAC?
I do have a static mapping for MAC address: 50:c7:bf:3d:4b:48 .
Also, that capture of the AP status shows modes b,g & n listed, which means you have all of those enabled. Mine shows n only. I have configured it that way, as all my devices are capable of using n. You can change the mode on the Wireless Settings page.
Mea maxima culpa! Setting corrected now.