Brian,this is not a linux-source bug but a linux-restricted-modules bug, because the madwifi driver is provided there. By compiling madwifi ng from subversion instead of using the modules provided by linux-restricted-modules 2.6.20 works (and provides increased signal strength on my setup, which is a nice bonus).
Here is my lspci for the device 03:00.0 0200: 168c:0013 (rev 01) Subsystem: 1385:5d00 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Step ping- SERR- FastB2B- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort - <MAbort- >SERR- <PERR- Latency: 168 (2500ns min, 7000ns max), Cache Line Size: 128 bytes Interrupt: pin A routed to IRQ 16 Region 0: Memory at fc600000 (32-bit, non-prefetchable) [size=64K] Capabilities: [44] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0-,D1-,D2-,D3h ot-,D3cold-) Status: D0 PME-Enable- DSel=0 DScale=2 PME- -- Madwifi doesn't work on Thinkpad T42p https://launchpad.net/bugs/78386 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs