Mirror + Subserf seam

Right to the point…

I seem to have created a weird seam combining the subserf and mirror modifiers. The subserf is below the mirror (as it should be) but there seems to be an inward seam where the mirrored mesh meets at the x=0 area. The suberf has a division of 2 and smoothing is applied. I’m using 2.58. I hope this makes sense. If you’re still confused as to what I’m talking about, I’ll try to explain more in depth below. If you understand what I am talking about, read no more.

Okay… so I have a mesh. To make this easy, let’s say I have a sphere, or half a sphere. I am mirroring the other half of the sphere along the x axis. I have went through made sure all the points are at x=0. When I apply the subsef modifier to the circle with a division of 2 and set it to smooth, there is a small inward crease in the circle where the meshes meet. I assume it’s because it’s to smooth the hard edge of the half sphere so it’s making it dip in a bit. Anyone know of a way to fix this? I hope this makes sense in my super tired state. Thanks in advance.

EDIT

I have spoken too soon. I figured it out quite quickly. At the center of the sphere I had other verticies thus creating faces on the x axis and it was trying to smooth those faces together. I just deleted the inside verticies (as I should have to begin with as they’re inside the mesh and wont be seen anyways) and all is well