Due to various API changes and some changes in the Makefiles of Linux, current version of the driver doesn't build any more on Linux 2.6.20.
After reading through various docs and sources I think I correctly adapted it to the API changes. Compiles and runs on a Debian Etch with a (manually installed) 2.6.20 kernel. Patch attached.
I'm using a DWL-510 NIC, lspci:
00:14.0 Ethernet...
2008-02-29 15:15:39 UTC in driver for rtl8180 + sa2400