I am not on lk so i missed your initial post; i apologize if
i am repeating things you might have tried out.
It does not make sense that it works in 2.2.16 but not 2.4.0.
How reproducible is this?
The only visible difference between the two appears to be the mss. It'll
be a shocker that would cause problems.
They both seem to be happily SACKing.
>From the traces it appears 188.8.131.52 is Linux, no? And your traces
must be from the Linux side, right? Why are those packets being dropped
only when using 2.4.0?
Force the MTU on linux to be 536+40.
If that doesnt fix it turn off SACK.
If that doesnt fix it i would start suspecting the NIC. What NIC
do you have on Linux? Might be alignment screw ups.
If that doesnt fix it, i would start suspecting windows.
Capture traces on both sides (windows and Linux side) for both kernels
preferably using -w option and post the URL.