Quote - ok as I thought. sorry mate.. you've mirrored the mapping. the ends of the cylinders are not mapped at all and you've got a streatched seam down each side where the overlapping UVmap's meet.

this is what we actually try to avoid in UVmapping.

Which cylinder? (Object File name) are you talking about?

And "Yes" you'd want to avoid that if you were going to use that map for a texture.  But, that isn't the point here.  There are no "unmapped" faces in that object. (In any of them that have a UVMap.  That's why they all had texture-checker png images attached to them - To check for that.) Put a texture checker on it.

PS - Better yet, open the object back up and relax the UVmap (if you have a tool that does that) along the bottom and top of the map.  You'll see the vertices move and the mapped top/bottom/side of the cylinder will be more apparent.