FC6 + Linksys RV016 network issue

[Drew Bertola]

Hi,

This problem might be better on the user list, so sorry if this is the
wrong place, but it is a serious riddle.

I have a couple workstations running fc6 at work.  They are both having
a problem pulling certain web pages.  I believe this is kernel related,
and have not been able to figure out why it happens, but here is what I
know...

Certain web pages do not finish loading.  This is browser independent
(tried firefox, lynx, links, curl, and wget).  The pages that do not
display include news.yahoo.com, slashdot.org, several others.  Pages
that do not hang and display nicely include drewb.com, (my own non-local
site), kernel.org, and others.

Loading web pages is the most obvious way to see this effect, but I
believe it's not strictly an http problem.

This only happens when our linksys rv016 (16 port router / vpn) has
firewall rules turned on.  With the firewall turned off, I'm fine.

CentOS 4.4 (w/ kernel 2.6.9), recent ubuntu live CD not affected.  They
work.

FC4, FC5, and FC6 do have this problem.  All updated.

WinXP / Mac OSX not affected.

kernel 2.6.12 built w/ fc6 config works (lots of warnings and errors,
couldn't start X, but could load slashdot.org in it's entirety using
curl, so I guess it worked.

I believe tcp_ecn is not the problem since I didn't play with it and
is(that would have been an easy fix)

What I need is a kernel that doesn't exhibit this problem that will
build on fc6.