BRad, here the question...
I've a Firewall (grsecurity on, iptables 1.2.5 patched), a linux squid-proxy that views internet by Firewall's nat.
On the firewall I load for first nat rules... after that INPUT chain that include -m stealt udp and -m stealth --syn rules...
Frequently http request are ended with a "Connection Reset by Peer"
I said "Frequently" because is a Random issue...