[BGY11]

You may want to check your wireless encryption. Some methods won't allow the router to work at maximum speed for 802.11n.

On my WNDR3700, I'm using WPA2-PSK (AES).

I also presume you are referring to the speed Windows reports, rather than the actual bandwidth (since even with 802.11n, you won't get anywhere near 130mbps speeds).

 

[BGY11]

You can also try going into Device Manager, opening up the properties of your wireless card, and changing these settings under the Advanced tab:

802.11n Channel Width for band 2.4: Auto
802.11n Mode: Enabled
Transmit Power: 5 (Highest)