Exactly....so have I ....that's why it caught me by surprise. Okay, I went thru all of it in FO3Edit and did the remove indentical, but it still comes up as a master. How/where can I manually remove it? I can't find where to do it in FO3Edit or in my GECK data. Sorry to be such a pain.
One thing I can think of to talk about, here.
What makes a file an .esp and not an .esm is actually not the filename. There is a little flag that is internal to the file which tells GECK that it's a master "esm" or a plugin "esp".
I suspect that the Syndey file is named .esp, but internally it has its .esm flag set. I say this because GECK never allows you to add, or retain, a real .esp as a master. In fact, GECK rips .esp files out of your master list if it notices them.
To undo this edit to the Sydney mod, you might try running "FO3MasterRestore" against your mod list, or, you could hand-edit that .esm flag out of the Sydney mod with FO3edit, if you know how to do that ...
At the point where the file is not actually an .esm internally, that's where stuff can start to make more sense as you go through this.
it is possible that the Syndey mod author accidently released the .esp with this flag set. I've done it a couple times myself with some of Phalanx' supporting .esps.