I think I have answered my own question (see post D-Link DWA-160 ....) One has to replace the rt2870sta module that openSuse 11.4 uses by default, with rt3572sta. My technique is probably bad, but this is how I did it.

First, get rt3572sta.
Go to YAST - Software Repositories - Add - HTTP
Enter a name (e.g. Wireless Divers) and complete the URL as follows (after the http://)
download.opensuse.org/repositories/driver:/wireless/openSUSE_11.4/
Having added this repository, go to YAST - Software Management
Look at what is in the Repository you have just added
You should find that Yast has automatically selected 4 files; the rt3572sta stuff!
Proceed with installing this selection.

Next, get rid of rt2870sta.
Go to System - File Manager - Super User Mode (root password needed)
Navigate to /etc/modprobe.d/ folder
Inside is a file 50-blacklist.conf - Click on this to open it.
Add to it the following lines
# I did this cos some idiot told me to
blacklist rt2870sta

and save.

Check if what you have done works.
Reboot and with luck your wireless adapter now won't work at all
Open a terminal and type
su (enter root password)
modprobe -i rt3572sta
Close the terminal
With luck, your wireless adapter will now show signs of life.

Make loading of rt3572sta automatic.
Go to YAST - System - etc/sysconfig Editor - System - Kernel - Modules loaded on boot
Type in rt3572sta
Reboot

If all goes well, your D-Link DWA-160 will now connect at 802.11n speeds (I get 270Mb/s instead of the 54Mb/s I always got with rt2870sta), and it will operate dual-band. The LED won't work, though, but I can live with that. Here are the results of lsusb, lsmod and iwconfig for me, after doing all the above. Have lots of fun .............

pierre@ATHLON64x2:~> lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 07d1:3c11 D-Link System DWA-160 Xtreme N Dual Band USB Adapter(rev.B) [Ralink RT2870]
Bus 001 Device 005: ID 04b8:0121 Seiko Epson Corp. Perfection 2480 Photo
Bus 002 Device 002: ID 0424:2504 Standard Microsystems Corp. USB 2.0 Hub
Bus 003 Device 002: ID 0471:0329 Philips (or NXP) SPC 900NC PC Camera / ORITE CCD Webcam(PC370R)
Bus 003 Device 003: ID 03f0:1604 Hewlett-Packard DeskJet 940c
pierre@ATHLON64x2:~> lsmod | grep rt
rt3572sta 550262 1
pierre@ATHLON64x2:~> su
Password:
ATHLON64x2:/home/pierre # iwconfig
lo no wireless extensions.

eth0 no wireless extensions.

wlan0 Ralink STA ESSID:"Belkin.9E54" Nickname:"RT2870STA"
Mode:Managed Frequency=2.422 GHz Access Point: 94:44:52:AA:3E:54
Bit Rate=270 Mb/s
RTS thrff Fragment thrff
Encryption key:8391-EC60-1A87-7A7F-38B1-8558-0537-EA3F Security mode:restricted Security modepen
Link Quality=100/100 Signal level:-62 dBm Noise level:-80 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

ATHLON64x2:/home/pierre #