I think I know what you are talking about because I noticed the first week I got my BlackBerry, if you run the setup and configure 2 seperate email accounts you will have nothing to worry about. The 2 different icons seperate the emails.
If you go into one of your inbox's and go options then email settings then in message services it shows you the same email address no matter which inbox you go into. That is nothing to worry about and I wouldn't mess with it either lol.
I think that is what you mean right?