Hi All. I’m using Blender 2.40 to make models for our open-source flight sim and I just ran into a strange problem. While unwrapping UV’s for the texture, I noticed I could not make a seam between two verticies on the missile cylinder. The strange part is that it has worked on prior missile models. Here is what is happening:
I first select the vert on the top of the cylinder. (you can see the seam I already made around the circumference)

Next, I select the vert on the bottom of the cylinder. The yellow line tells me I have the two verts lined up correctly.

I select edge specials to mark the seam,

But when I go to the UV face select mode, there is no seam! The other seam I made is visible at the top of the missile.

I thought maybe blender wasn’t displaying the seam, but it was still there. So, I selected the cylinder faces and unwrapped. Instead of getting the nice, even rectangle I expected, I got the smushed result that indicates no seam.

Does anyone know what’s going on? Any assistance would be greatly appreciated!