UV Unwrap issues - Blender n00b

Hey Guys,

I’m trying to unwrap my stem that I have created but as you can see the UV Wrap is coming out all odd on the UV/Image editor. I have marked a seam and I can’t see what I am doing wrong.

This is what I’m trying to achieve and I’ve followed it step by step. Any ideas?

Here is a link to the .blend file I am using.

Select all the vertices and remove all those unneccessary double vertices (W / remove doubles). Then add your seams and unwrap

Just select a vertex on your object and move it to see you have a duplicate as well. Take more care with your modelling