I've just installed Xubuntu (totally new to Linux) with success straight off the alternative installation disk on an old PII tower I've cobbled together. It is running like a dream despite the size of the system and seems to be making good use of all the hardware currently in the box. Except the wireless network adapters.

Now, assuming I can't connect via physical ethernet to the router I'm using (A DLink DSL-G604T with WPA-PSK security running) I have 2 wifi devices plugged in - a Belkin F5D7000 PCI card and a DLink DWL-G122 usb wifi adapter, both of which are in working order.

With both in the machine, my os is recognising them inasmuch as I have, in my network settings window, options for "wireless connection eth0" when my pci card alone is in, and "wireless connection rausb0" as well when I add the usb adapter and reboot.

I appreciate that WPA isn't a tweakable option in the networking window and that I have to fiddle with the /etc/network/interfaces file, by going into terminal and typing gksudo(which apparently allows me to change system things) mousepad /etc/network/interfaces and that brings up a text editor with the file loaded, that I can save post-editing which I couldn;t do opening the file through the browser window.

Now, I've added the following:
replacing ra0 with eth0 and againrepeating the script with rausb0. Then I've saved and in the command line "entered sudo ifup rausb0" (and also eth0) and nothing has happened. Then rebooted with the changes in the interfaces file saved and again, no change, no flicker of life from the leds on my adapters, still showing in the network window though and no hint as to where to go from there.

I'm guessing I'm not adding the right things to the script, but I've reached the limit of my understanding.

Also, lspci tells me the PCI wifi adapter is a BroadcomBCM4306. Says Belkin on the card and the box. Very odd.

So.... HELP!!!111 and all that. Thanks.

/apparently yes, it is the BCM4306.

Welcome to LQ!

I'm going to jump around a bit in answering your questions, but hopefully it will make sense by the end.....

Broadcom makes the actual chips in the card and sells them to lots of vendors (Dell, Linksys and others). The important bit in all of this is that it is the 4306 chipset, and that means it is likely using the bcm43xx driver. In a console, check the output of lsmod and see if it is loaded when your PCI card is in. In order to get bcm43xx working properly, you need to install firmware, and I'd be VERY surprised if Xubuntu has done that. Check out my linux site (link in sig) because I have a section on installing firmware using a program called fwcutter and a Windows driver. Once you've got that done you're ready to tackle WPA.

I'm not sure this is entirely right. There is a program called wpa_supplicant that handles WPA encryption, and that usually isn't invoked from the network/interfaces file. In fact I use a script to start it when I bring my wireless card online. I've got a section on installing and using wpa_supplicant on my site, but I would suspect that you can get the program from your Xubuntu repositories. I know Ubuntu has it available.

That is pretty close. The sudo command allows any command to be run with root privileges, and since the *buntus have pretty much done away with the root account (not entirely true, but close enough for now), you use sudo to do the kind of things root normally does. Now in my opinion, that is a gross violation of what sudo was intended to be used for, but that is a rant for another time. Since configuration files usually need root privileges to edit, you need to have an editor with root privileges in order to save your changes.