I'm sorry, I don't know mutch about blender, tough I have a problem i dont know how to solve. I created a thick glass bottle, of the witch I duplicated the interrior faces to make a new object to do the liquid inside. I went in the edit mode, selected the faces I wanted to copy and duped it with "shift+D". Then I think I pressed "P" to separate de dupe. Now i try to make a dupe of that liquid to make it flow out of the bottle, and i simply need the dupe of one face of it. So I go to edit mode and do as i did to make the liquid from the bottle faces... but as soon as I'm back to the object mode, and i want to move the duplicated faces, every thing moves with it... i played around and tryed things, and while doing so I realised that if I dupe the liquid object in object mode using "Shift+D" and press "nump0" to place it where the original is, they move together, and if i dupe it and place it somewhere els, they are separated. Also if i pick one of the two separated objects and make it intersect with the other one, release my left mouse button to place it there, and then try to mode it again, they both move together, but not at the same speed. i realy dont understand what is going on and I'm shure its realy dably explained, so what I'll do is make a screen cap of my Outliner and recored the behavior of the objects and upload those to help you understand. 