I was able to get the Syntax USB-400 wireless USB to work under Debian Linux by downloading and building the linux-wlan-ng-0.2.1-pre20 modules with all drivers.
You are going to need the source code to your kernel at /usr/src/linux (create the symbolic link or rename the folder). Copy your distributions configuration file from the /boot/ folder (Debian names it something like config-2.6.5). You will have to have some kernel parts compiled in order for the linux-wlan-ng module to work. I ended up creating a whole new kernel.
Run the ./Configure from the linux-wlan-ng folder. It asks you some basic setup questions and attempts to load everything. This didn't work for me. I then ran 'make all' and 'make install' to have all modules built and installed into the correct /lib/modules/'uname -r'/ folder. Run 'depmod' and 'modprobe -l | grep prism' to see if you have the prism2_usb module. Then load the module with 'modprobe prism2_usb', the 80211b driver also will get loaded.
I was also able to have hotplug (
http://linux-hotplug.sourceforge.net/) recognize my toy by copying the output of 'cat /lib/modules/'uname -r'/modules.usbmap | grep prism2_usb' to /etc/hotplug/usb.usermap. I think this is what I used 'cat /lib/modules/'uname -r'/modules.usbmap | grep prism2_usb >> /etc/hotplug/usb.usermap'
Now I don't have to have the USB-400 plugged into my laptop until I am ready to use it.
To have it connect to a wireless network, I had to change the /etc/network/interfaces to include:
auto wlan0
iface wlan0 inet dhcp
wireless_mode managed
wireless_essid default
#default was the name of my router I wanted to connect to.
