You can't just unwrap something, slap a texture on it and expect the texture to line up at the seam..lol. It just does not work that way. Even if you filled your texture template with a seamless texture, it will still show a seam where you cut the model to unfold it. You must match the seams at the area that was cut...both sides so that it's a smooth transition across that area when you apply it to your object.

Laurie