I discovered a bug in the ath5k kernel modul in Kernel 3.2.14 (and also in the 
latest Ubuntu backport modules for this kernel).

If I try to upload larger files (at least several kb), the upload starts, but 
comes to an immediate end. Sometimes it goes again on for some seconds, but 
only to immediatelly halt again. Because of this uploading a file of 1 MB via 
dropbox, firefox or my mail client can take 8+ hours (where I normally have an 
upload rate of 100 kb/s). However, uploading via Ktorrent works fine.

If I use the ath_pci module instead, everything is fine and works normally. 
Hence, I think the bug has to be in the ath5k module.

I attatched three files with more relevant information. One is the 
wpa_supplicant.conf the other one contains the output of the dmsg command and 
the file named Bugreport contains drivername, kernelnumber, iw output, and a 
script I used for the wpa supplicant. If you need more data, please feel free 
to contact me. 

Greetings,

Markus

P.S.: If the bug is fixed and in the fix is in the newest compat-wireless, is 
there an easy way for me to know. Because then I'd switch back from ath_pci to 
ath5k.