Problem with internal webserver, squid transparent

["Charles Regan" <charles.regan@xxxxxxxxx>]

I am doing a transparent redirect using a bridge.
(iptables -t nat -A PREROUTING -i my -p tcp --dport 80 -j REDIRECT
--to-port 3128)
WEBSERVER ---- ROUTER ----- SQUID ------ INTERNET

Doing this make my webserver not accessible from the internet (port 80).
Any idea whats wrong ? How can I use iptables to not redirect my webserver?
I've tried adding to squid.conf

acl Websvr1 dst 1.1.1.1/255.255.255.255
no_cache deny Websvr1

Didn't work.

thanks
C.