I'm having an odd problem with my setup. Currently I have two RT-N16's configured as AP+WDS on channel 1, 20MHz width, using WPA2-AES. This all works fine. I want to try and maximise the bandwidth by switching to a 40MHz channel width, but when I set this in the Basic wireless settings on both routers (Lower control channel), the actual link is unchanged, and continues to use a 20MHz channel, even after a reboot. I've checked the relevant parameter in nvram and it looks correct (wl0_nbw=40), so why is it being ignored? Is it simply not possible to use a 40MHz channel width in an AP+WDS configuration? Is there a technical limitation involved?