Airport transmit problems (Linux only?)

[Romain Kang]

On my iBook (first generation 500 MHz iceBook), I've been seeing
problems where transmitting data via Airport seems to stall, while 
the same problem does not seem to happen when running OS X.  I  
think the problem started about a month ago.

My home network runs on an SMC access point with combined switch
and router (7004WBR).  I'm running a 2.4.19 kernel that I built
from sources downloaded from kernel.org, though I don't think this
should make a difference vs. the YDL; the problem has appeared
under both YDL 2.2 and 2.3 (upgraded about 10 days ago).

Typically, I attempt to load a web site that uses cookies, and
the browser (usually Opera) shows a status "Sending data to ...".
I've seen this last as long as 12 minutes at a time before giving
up and plugging in the hardwired 10/100 port, which works without a
hitch.  The page load also works if I reboot the iBook, but not if
I turn off the Airport interface (ifdown eth1; modprobe -r airport)
and restart it.  The problem often happens within a few hours of
rebooting 2.4.19, but I have run OS X for days without a glitch.

I've also seen this when attempting to upload via scp or FTP.
During a problem FTP upload, I used a hard-networked computer to
login to the remote host and run tcpdump there, while observing
tcpdump on the iBook.  The larger outbound iBook packets didn't
show up at the remote end.

The following ideas occur to me:
- Try running an older kernel
- Try getting the Airport replaced under AppleCare
  (may be difficult, since OS X seems to work OK)

Does anyone have other suggestions?
 
Regards,
Romain