No more space in this STA's PS mode buffer

[Doug Yeager]

i have a few AP's in downtown knoxville serving coffee houses.  i review 
the dmesg logs frequently to see what is going on.  every now and then i 
get this log messages.  usually follows a resetting of the AP card.  my ap 
is wmp11 pci card.  it would be much appreciated if someone could interpret 
this message for me.  what is PS mode buffer?  can i prevent this w/ some 
setting?  the results of this  are not horrible as only the client that 
causes this usually cannot get back on....everyone else is usually o.k. 
until i reboot the AP.  one time i was able to run down one of the clients 
on the wlan and beat him up and take his laptop.  i found a dwl-650 card 
inside if that helps at all.

dmesg log where the trouble starts:
---------------------

wlan0: 00:04:75:c4:36:b1 auth_cb - STA authenticated
wlan0: 00:04:75:c4:36:b1 reassoc (len=24 prev_ap=00:06:25:09:0b:31) => 0(0) 
(OK,
  old AID)
wlan0: 00:04:75:c4:36:b1 assoc_cb - STA associated
wlan0: STA 00:04:75:c4:36:b1 TX rate lowered to 55
wlan0: STA 00:04:75:c4:36:b1 TX rate raised to 110
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
wlan0: STA 00:04:75:c4:36:b1 TX rate lowered to 55
wlan0: sending disassociation info to STA 00:04:75:c4:36:b1(last=22325356, 
jiffi
es=22355456)
wlan0: STA 00:04:75:c4:36:b1 TX rate lowered to 20
wlan0: sending deauthentication info to STA 
00:04:75:c4:36:b1(last=22325356, jif
fies=22355556)
wlan0: Could not find STA for this TX error
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
wlan0: STA 00:02:2d:66:cb:0c TX rate raised to 55
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer
No more space in this STA's PS mode buffer