optimizing traffic to a web server

Hi,

I have a Linux server and provide Internet access in the neighborhood
and I also run a web server on the same machine. 

Although our external connection is not bad, the access to the web
server from outside is awful - the web pages always require "Try
again" when accessed.

Do you think I can prioritize the traffic to the web server? How? I
have a traffic shaper of the internal and the external interface. I
use "tc" with HTB and "iptables" for that purpose. I mark the packets
and then filter them. I just don't seem to have written the write
filters.

Thanks in advance!

-- 
Kamen