Shader preview and 3D preview window don't match

[Stranded]

Okay, I know I'm a noob here at the site and to the software itself but this just seems counter-intuitive to me..

As you can see from the attachment, the shader preview has the fake stones off the dirt trail like they should be. But the 3D preview and ultimately a render show them all over the trail. Why are they different?

Thanks in advance. I'm sure it's a box somewhere I haven't put a check in but I'm really confused on this one..

*Edit - fixed, thanks Dune... still not where I want to be but at least they are off the path.

[Dune]

Are you sure the camera is on the path? Is your dirt trail a painted line or an imported mask? You can check where it is by adding a surface shader at the end of the line, make it a test color and plug the mask or painted shader in the masking input. Disable (select and hit 'd') before rendering of course.

[Stranded]

Are you sure the camera is on the path? Is your dirt trail a painted line or an imported mask? You can check where it is by adding a surface shader at the end of the line, make it a test color and plug the mask or painted shader in the masking input. Disable (select and hit 'd') before rendering of course.

It is an imported mask and your clue helped me figure it out. I actually have TWO masks for the scene. One for the dirt trail and another one which was made in conjunction with but on an individual layer  so they would work nicely as separate masks. I failed to notice it was the WRONG mask that I was looking at in the 3D preview.

Thanks Dune! You are a life saver....