It shouldn't depend on the hardware used as long as your ndiswrapper is working all right, or you're using native drivers that work all right. I myself would start off by making sure the thing works at all:
should tell you if (at least one of) your devices work (others should give "no wireless extensions"). After this, if
eth1 (For example) was the device that did have 'wireless extensions',
Code:
iwlist eth1 scanning
should provide you with some access points information (I'm not sure if it makes difference if you run it as root or as a regular user, try both if you're not getting anything). Then, when you know the ESSID of your preferred access point, try to connect to it (as root):
Code:
iwconfig eth1 essid <ESSID here> key s:<key here>
dhclient eth1
If eth1 is not the wireless device, change it. In place of
<ESSID here> type the name you got using
scanning. If your key is ASCII key, use
s:keyname, if it's not (i.e. it's hexa) use just
keyname without the 's:'. After that make sure dchp information is obtained, running either
dhclient or
dhcpcd depending on which one is installed on your system.
If that works, your device works, and the problem is with the graphical tool (I found out that Gnome 2.16 and at first in 2.18 the Network Manager applet didn't do something right with the keys and could not connect, but now that I did some updates, 2.18 can manage my wifi network's key and gets connected). If the command-line stuff did not work then you should think why that is, and get to the graphical tool only after that.
If you get any errors, problems etc. post here and let us know. It is possible that it's just the graphical tool that isn't working (note: when typing the key for it, make sure it understands the format -- is it ASCII, hexadecimal and WEP or WPA when you need wpa_supplicant -- and so on), but that's made sure with the command-line tools.