Problem with assigning materials to vertices

So, I have a mesh. I assigned 4 different materials to it. The first one is just the default for every vertex I don’t want to bother. After I assign the other 3 materials to every part of the mesh besides like 200 vertices, I make sure they assigned correctly by deselecting everything and selecting the vertices assigned to the default material and more than the 200 vertices show up. I have 2 different materials assigned to the same set of vertices. Is this a bug? Blend: http://www.pasteall.org/blend/24581

Can you highlight what you think is wrong with your blend file ? After a quick look at it I don’t see anything standing out as being a problem with the assigned materials

I have 2 different materials assigned to the same set of vertices.

You don’t assign materials to vertices, you assign them to faces.

Here is my process, I select the container of the lighter and assign the glassy material to it. Then I hide that selection and select the black glossy material vertices and assign them. Then I hide that selection and select the rest of the mesh by pressing A. Then I assign the clear glossy material to that selection. So, everything except the little tube inside the container should’ve been manually assigned to a material. So I unhide everything and select the default material and hit the select button and then some faces light up when they shouldn’t.