WiFoobar

This is taken from the HardwareSupport / Components / WirelessNetworkCards section of ubuntulinux.org.

D-Link

DWL-520+

acx100

Yes

Yes

Yes

Just Works, only distro that autodetects this one

The strange thing is that my DWL-520+ wlan card uses the acx111 Chipset. This is my lspci -n output:

0000:00:0c.0 Network controller: Texas Instruments ACX 111 54Mbps Wireless Interface
Subsystem: D-Link System Inc: Unknown device 3b04
Flags: medium devsel, IRQ 5
Memory at dfffa000 (32-bit, non-prefetchable)
Memory at dffc0000 (32-bit, non-prefetchable) [size=128K]
Capabilities: [40] Power Management version 2

Later in the same page I found:

"...Does not work for me unless I recompile the pci_acx module with latest patches. After that it works. WEP not yet supported for acx111 cards..."

Bad luck...