Oops I was wondering where you got moving from....but no, this is all copy. Sorry.
Move and copy are different, here you say move
I do have a couple of 802.11g clients around here so I have no choice but to run mixed.
Maybe your seeing CRAP N speeds is why you don't see a difference when you turn on G/N mode There is NEVER a reason to run G/N together on the same hardware.
Ive been running mixed for years now BudMan and this problem never occured. A solution to change it to N only is not possible.
You are running mixed - change that to N only.. And turn on rts/cts and enable rts and enable short preamble. What channel you should run would depend on what is in your area fire up say inssider and look