Kernel used: linux-image-2.6.31-11-generic

Ath5k modules used from linux-image-2.6.31-11-generic:
user@k9-10-32bit:~$ lsmod | grep ath
ath5k                 123940  0
mac80211              181236  1 ath5k
ath                     8060  1 ath5k
cfg80211               93052  3 ath5k,mac80211,ath
led_class               4096  2 ath5k,thinkpad_acpi

Ath5k modules used from linux-backports-modules-2.6.31-11-generic
user@k9-10-32bit:~$ lsmod | grep ath
ath5k                 121988  0
mac80211              210376  1 ath5k
ath                     8444  1 ath5k
cfg80211              130536  3 ath5k,mac80211,ath
led_class               4096  2 ath5k,thinkpad_acpi

Madwifi 0.9.4.1 compiled from source:
user@k9-10-32bit:~$ lsmod | grep ath
ath_rate_sample        12732  1
ath_pci               203476  0
wlan                  226416  5 wlan_ccmp,wlan_scan_sta,ath_rate_sample,ath_pci
ath_hal               303104  3 ath_rate_sample,ath_pci

Atheros hardware used:
user@9-10-32bit:~$sudo lspci -vvnn
03:00.0 Ethernet controller [0200]: Atheros Communications Inc. AR5212 802.11abg NIC [168c:1014] (rev 01)
        Subsystem: IBM Device [1014:058a]                                                                
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- 
        Latency: 0, Cache Line Size: 64 bytes                                                                
        Interrupt: pin A routed to IRQ 17                                                                    
        Region 0: Memory at f7f00000 (64-bit, non-prefetchable) [size=64K]                                   
        Capabilities: [40] Power Management version 2                                                        
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0-,D1-,D2-,D3hot-,D3cold-)                 
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-                                                  
        Capabilities: [50] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable-                      
                Address: 00000000  Data: 0000                                                                
        Capabilities: [60] Express (v1) Legacy Endpoint, MSI 00                                              
                DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 <64us                      
                        ExtTag- AttnBtn- AttnInd- PwrInd- RBE- FLReset-                                      
                DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-                           
                        RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop-                                         
                        MaxPayload 128 bytes, MaxReadReq 512 bytes                                           
                DevSta: CorrErr- UncorrErr+ FatalErr- UnsuppReq+ AuxPwr- TransPend-                          
                LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <512ns, L1 <64us           
                        ClockPM- Suprise- LLActRep- BwNot-                                                   
                LnkCtl: ASPM L0s L1 Enabled; RCB 128 bytes Disabled- Retrain- CommClk+                       
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-                                       
                LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-           
        Capabilities: [90] MSI-X: Enable- Mask- TabSize=1                                                    
                Vector table: BAR=0 offset=00000000                                                          
                PBA: BAR=0 offset=00000000                                                                   
        Capabilities: [100] Advanced Error Reporting <?>                                                     
        Capabilities: [140] Virtual Channel <?>                                                              
        Kernel driver in use: ath5k                                                                          
        Kernel modules: ath5k, ath_pci