I finally was able to get my WRT-150N wireless router into 40 MHz wide channel mode without breaking the ability of my Mac OS X wireless clients to connect using 802.11g. However, I noticed that signal level on my MacBook Pro, when connected with 802.11n, was about 20-30% lower when the wireless router was set to 40 MHz wide channels rather than 20 MHz standard channels. Is this expected? I am assuming it could be the result of the transmitter in the WRT-150N having to spread its output over double the frequency range. Jack ps FYI, the solution to the problem of 40 MHz wide channels breaking Mac OS X wireless G clients was to upgrade to the Linksys v1.02.0 beta firmware.