I have two PCs that appear to have a problem sharing network bandwidth.  I have a Proxim AP-700 connected to my server and two Linux boxes.  When I try to pull files (using scp) from both Linux boxes, one will eventually loose completely, stalling until the other completes.

Both stations have the same Atheros 5212 and madwifi 0.9.3.

Both stations report the same SNR (35-40) on the Proxim AP.

If I bring my WinXP laptop into the picture and grab from all three stations, the WinXP laptop grabs half the throughput and the other two Linux stations fight over the remaining bandwidth with one of them eventually stalling.

I've tried a Cisco AP with no change. 

I've tried different Atheros cards.

I've tried 802.11b and 802.11a.  I've disable all encryption and set everything to static IPs trying to simply the scenario.

Any ideas why these two Linux boxes fight over bandwidth, always with a clear loser (50Kbps or none at all)?  I thought the AP was basically "in-charge" of bandwidth sharing between stations, but these problems only seem to follow the Atheros stations?