Turning off wide channels didn't seem to do anything. I tried it when I saw you first post about it...

I can't keep that 4.7MB/s I mentioned earlier consistently from this room. From the same room as the base I can actually get a solid 6MB/s.

Here are the stats (Rate sometimes jumps to 80. Mostly stays where it is though).

5GHz: Signal -74, Noise -90, Rate 54, Type 802.11a/n

With Interference Robustness and Wide Channels turned OFF:

5GHz: Signal -71, Noise -93, Rate 52, Type 802.11a/n

From the same room as base:

5GHz: Signal -57, Noise -91, Rate 135-162 (sometimes jumps to over 200), Type 802.11a/n (without Int.Robust)

5GHz: Signal -50, Noise -93, Rate 130, Type 802.11a/n (with Int.Robust)

For comparison, my Squeezebox which sits about 8" away from the base station:
2.4GHz: Signal -26, Noise -96, Rate 54, Type 802.11b/g