I suspect what's happened is that you've got messages in different encodings, so there are different parts of the file that are invalid no matter which encoding you try to choose.
And gedit doesn't seem to have an option to leave a file unconverted (often called "raw" or simply "no" encoding), which is pretty lame, so I suspect you'll have to use a different editor.
Ignore all the people telling you to use anything based on vi - it's a horrible editor if you don't already know how to use it. (Ditto for emacs, although possibly not quite so bad).
Aha, +1 informative. Thank you. I might file the lack of ability to use raw in gedit as a bug...it's silly. And yah, I stay away from vim and emacs; I just don't have the inclination to learn them, since I never have had any need. I'll try some alternative text editors. Regards, Bnonn