ar9170usb broken partly 2.6.36

It appears to me that latest Arch linux kernel26-2.6.36-x and my atheros based card Dlink DWA-160A (ar9170usb) have a little problems with connection. iwconfig appeared to show 300Mb/s-1Mb/s speed. As what i have read about the driver ar9170usb doesn't yet support 802.11n ? But if there is upgrade its not working right for me. My connection is very unstable and very slow due this. Connection speed to router and so forth is around 1kb/s - 27kb/s ping is between 200 - 10000. Problem appears to be greater during the load of network. Problem disappeared while dropped kernel to verion 2.6.35.8-1 (arch linux kernel). Dmesg is clear of errors.