Inconsistent UV unwraping I have recently modelled a lego figure and wish to UV unwrap it. 
This has mostly been easy, as you would expect, however I am running into several problems, all of them being either distorted unwraps, or inconsistent unwraps.

The following is the top hole of a lego figure leg, the one I am having trouble with:



The other hole, however, does not unwrap like this at all. It unwraps as a clean and proportionate circle, as I would expect. 

Why is this happening? I am new to UV unwrapping, so if I am totally misunderstanding seams please feel free to let me know and point me in the right direction. 

I am using UV unwrap.
 I have already:


Applied scale and rotation (though not to the object I used to cut the whole out from, it was a default sphere).
Removed doubles
Recalculated Normals


I would appreciate help with this particular issue, as well as any tips as far as UV unwrapping goes. 

Thanks for reading.

The .blend file of the leg
Instead of manually marking seams, use smart UV unwrap. Smart UV unwrap breaks the mesh into islands based on angle threshold. Since the lego leg has very nice geometry, the default angle limit of 66 degrees works well. 



In UV editor, press  U > "Smart UV Project".