Right. So I have been busy testing my WoW latency all weekend, and I seem to have fixed it all on my own. Firstly, I have a 384k line that I play on, and although it is a bit slow, it caters for my WoW needs and it doesn't cost me an arm and a leg.
Now a 384k line has a maximum possible download of 48 kilobytes per second, and a maximum upload of 16 kilobytes per second. Under normal WoW gaming circumstances you should not exceed this. I was wondering if my usage was the case, so over the weekend I fired up Networx (awesome little bandwidth monitor program, and its free!!) and had a look at my up and download rate while I play. Every time that I get DC'ed, Networx shows that I exceeded the up and download rate of my line. Am I correct in saying that once a program tries to exceed those limits on my pc that it basically saturate the line and the connection drops? Also take note that this only happens in our 25man raids, not whilst doing dailies or dungeons.
To fix it I got myself two new addons. The first one is called Spamalyzer, and the second one is called Smart Addon Blocker. I figured that the only reason I exceed the limit and get disconnected, is because other people in the raid and guild's addons sends me unnecessary messages, which causes me to DC. Tested last night during raid to confirm.
Hope this helps anyone out there that had a simular problem as me.
I've been looking at addon traffic as well and trying to understand what the impact might be of raid addons and such on a 384k user - I don't have any high level characters so this isn't something I could really put to the test myself.