I am currently trying to set up wireless internet with a DLINK DWL-520 rev e on Mandrake LE 2005. I am linux newbie so please keep that in mind when posting replies.

The DWL-520 e doesn't have permanent firmware so I have to use the hostap driver and load the firmware after each boot. I am currently doing this:

modprobe hostap_pci
hostap_fw_load wlan1
iwconfig wlan1 mode Managed key {my key here} essid "Wireless"

At this point I have a connection to my network and iwlist scan shows two available networks.

However, when I try dhclient to get an ip address I have no luck - dhcpcd also failed.

I was previously using Fedora 4 and was able to get on the internet using this same method but I would have to dhclient -r and dhclient again every few minutes - also sometimes when booting it would fail to load the firmware. I was hoping that I would have better luck with another distro but now I can't get an ip address.

Any ideas would be welcomed.

emarks,
I had a similar problem (and solved it just yesterday) with the DWL-G510 card. I too couldn't get dhclient or dhcpcd to make an association, using a freshly installed LE2005.
In my case, the output from dhclient said that the router returned an IP, but dhcp rejected it.

The problem was that I hadn't used Harddrake to set up the LAN. I was so busy questioning stuff in the wireless part of Harddrake, I hadn't thought to set up the LAN part, and DHCP needs that information to make the association. The information you'll need is minimal (and you probably have it already) - You'll get to choose the wireless device (I think, since you've already done the modprobe, it'll be the wlan1 choice for you), the essid as assigned by the router, the channel it's using, the WEP (if you're using it - I suggest turning that off in the router and by using iwconfig, if you can, until everything is working), and a hostname, if one is assigned (I suspect that the hostname is quite optional). There's a checkbox there in the harddrake LAN setup wizzard to bring up dhcp on-boot that you'll probably want to check. Worked like a champ after that.
Hope I didn't miss anything for you.
Good Luck
J