I use DWA-643 with my ASUS F3Ja laptop and I stuck with a known problem of DWA-643, which prevents laptop from shutting down correctly.
Recently I tried to search a bit about ExpressCard known issues and found out, that many Apple users admitted they faced a similar problem (Apple laptop + some ExpressCard modules, such as Wi-Fi modules, cardreaders, etc = laptop restarts instead of shutting down). Finally I found a useful comment of Apple's tech specialist:
https://developer.apple.com/library/mac/qa/qa1517/_index.html . I'm totally noob in electronics, but that comment explains clearly, that some modules' manufacturers do wrong implementations of ExpressCard standard in their products, hence it's likely, D-Link has implemented wrong connection scheme in DWA-643, so that most of us stuck with the previously described problem. Next, I found a scheme for ExpressCard slot:
http://www.allpinouts.org/index.php/PCI_Express_Card_and_PCI_Express_Mini_Card . And I wondered if that "wake#" (number 11) pin was the cause of the problem. The scheme says, this pin is "optional", not mandatory. And I tried to cover it with a narrow piece of scotch tape. If you observe the connection plug in a way, that the row of pins is at the bottom, the numeration of pins starts form the right end. 11th pin is short and it's located between two long pins. Also, if you compare first left pins with the scheme, you will ensure, that long ones correspond to GND. Hence, the direction of pins' count is right.
After sealing the 11-th pin I inserted DWA-643 and tried to power up my laptop. Everything is fine now, and my laptop is able to shutdown normally. I use driver ver. 6.0.3.67 (2007) from
http://support.dlink.com/ProductInfo.aspx?m=DWA-643 , and connection bandwith is 300 Mbit / s.
DISCLAIMER OF WARRANTIES AND LIMITATION OF LIABILITY:
The "solution" for the problem is supplied “as is” and all use is at your own risk. I'm not tech specialist, I just described the solution which worked for me fine.