Sending Domain Rep

Hey guys

So this is a rather complicated question.. hopefully someone with experience in email traffic can shed some light here.

I have a buyers list in the MMO niche that I've been mailing and getting great results from. Ive been mailing it under pen names.. and I've run into a little issue. When I send mail under one name (list owner), I have no issues. When I mail under my name, although I get very low spam complaints because I give them free content, my messages start going into the spam can without warning. I use a dedicated IP that has been warmed up and gets me close to 100% deliverability everytime when I mail.. and I use it for both domains.. So I know its not an IP issue.. I can create a message and test send it to my email address (when mailing as myself with my domain) and one day it will go into the inbox, the next day into spam, without sending anything in between...

This is driving me NUTS. Im thinking it has something to do with sending domain rep... anyone ever run into something like this before??