I am highly suspicious about the kernel settings. Surfing the net I found this option in the kernel that controls TCP Explicit Congestion Notification. Would this option be related to my problem (CONFIG_INET_ECN=y)? I guess that it won't hurt to try recompiling the kernel with this option turned off, if it exists in the 2.6 kernel. Something in the back of my mind tells me that the Linksys is breaking some tiny, little TCP/IP standard on which FC3 depends.
You don't need to recompile the kernel to disable ECN. To do this straight away, do:
# echo 0 > /proc/sys/net/ipv4/tcp_ecn
However, you may find that "0" is the default value of this parameter before you did this.
If not, you can make it the default by adding to /etc/sysctl.conf:
net.ipv4.conf.tcp_ecn = 0
Paul.
