This worked:

1. If you want to center the elements to the centerline of your canvas, then Command+A (Ctrl+A)
2. If you want to center to an off-center element make a marquee selection, PS will use its center point to align (vertical or horizontal, depending on what you're trying to center
3. Now, Command+Click (Ctrl+Click) (or Shift+Click) the elements you want centered.
4. Press V to get the Move Tool and click the align button up top that you want (vertical or horizontal)
5. Your elements should be centered according to where your marquee selection's center point is.

Cheers!

This worked:

1. If you want to center the elements to the centerline of your canvas, hit Ctrl+A
2. If you want to center to an off-center element make a marquee selection, PS will use its center point to align (vertical or horizontal, depending on what you're trying to center
3. Now, Ctrl+Click (or Shift+Click) the elements you want centered.
4. Press V to get the Move Tool and click the align button up top that you want (vertical or horizontal)
5. Your elements should be centered according to where your marquee selection's center point is.

Cheers!