Here is your problem:
-A OUTPUT -p tcp -m tcp --sport 80 -j REDIRECT --to-ports 8080
-A OUTPUT -p tcp -m tcp --sport 3128 -j REDIRECT --to-ports 8080
Edit: Check out http://www.ghacks.net/2010/06/14/int...n-to-iptables/
Now each chain can handle the packet traffic in one of four different ways (actions):
ACCEPT: Allow the packet in/out.
REJECT: The target device will reject the packet.
DROP: The packet is immediately dropped and the target device never sees said packet.
RETURN: Go to another chain in your table as if it never saw the rejecting chain.