Thanks Merlin, that was it. I remember turning that on when I set up this new firmware but I could not see any new function so I turned it off again. After a reboot now it shows "Enabled" for h/w acceleration.
BTW, it seems the IPTraffic on/off option is offered in AP mode but the function only works in router mode?
That's correct. I just never really bothered tweaking what's available and what isn't while in AP or Repeater mode.