Azureus and Mcafee firewall

[Gasmeter]

Hi....Could some one help please ? For ages I have searched the net looking for help on ways to use azureus along with Mcafee firewall but I just dont seem to be able to get the same download speeds that I was getting. I have set up mcafee by letting the programe have full access to the net but am unsure about this port forwarding thing thats meant to be done as well (if its needed to be done at all this is). Also the health status light stays yellow now all the time and the download speeds varry from 5kbs to 20 kbs but I used to get a steady 50 / 55 kbs. Im a complete knob when it comes to trying to set this up and would like step by steps on how to set it up right once and for all. Hopefully this wont take up too much of someones time and would really like the help please.
Im using Windows xp pro with sp1 a speed touch adsl modem with a 512 connection and Azureus 2.1.0.4 the latest version and Mcafee Security suite Pro

Many Thanks in Advance.