802.11n Slow

I’ve got exactly the same error.

The PC connects at 130 Mbps (why 130? why not 125, or 135?), and no more then ~25Mbps through the wireless.

The board is a brand new RB751U.

An another noticed thing, see the attached file.
I don’t think antenna mode should be there. N can use multiple streams, not just one.
751.PNG