Spacing Tool problem
If you want to use the Spacing Tool with your circle, you will need to adjust object's Pivot or create a box that is skinny in Width instead of fat Width the way you have it. Also, don't use "Objects at Ends" if you want evenly spaced and have no overlaps. Use "Space from Start, Specify Number" instead. (See attached)
Below topics cover the basics of transforming and copying objects using its Pivot and/or Coordinate System.
More Info:
Adjust Pivot Rollout
Reference Coordinate System
Hi. Sorry, I should have explained better. When I meant "skinny," I meant make the Box's width small in compasion to its Length(depth). You can see the object's dimensions in Object Properties (right-click object). It does not have to be skinny. I just made your domino box this way because of the way your Spacing Tool was orientating your object based on its pivot's orientation. Instead of adjusting Pivot, you can also rotate the spaced objects by selecting all and rotate on its Local Z axis by . On its X, then Y if it was built so that its height corresponds to its shallow depth. (See attahced files)
Example of Pivot adjusting: When you create a Primitive Box object from the top view, the Box's Pivot will be at the grid level aligned to World. If you try to rotate this, it will rotate about its base, not its center. Not every object will need to have its pivot at the center. In your original post, your box was probably built in such a way so that the shallow depth corresponds to object's height in Max. If you extruded a domino-shaped Rectangle and applied Extrude to give it depth, then your domino is lying on the grid. To adjust the Pivot, one would typically go to Hierarchy panel, choose "Adjust Pivot Only" and adjust(Transform, Rotate) the orientation of your object's pivot in your viewport. In my example, I just made a Box that was standing. This may not be what you want because you might want the domino piece to be wide, tall, and shallow in depth.
Whenever you transform, scale, or create array of objects in Max, Max needs to know where the object's pivot is and the orientation of its axes. This is even more important when there is a reference object involved such as your Circle.
Please take few minutes reading about the topic in the links to the pages in my previous post. Steve's reply also explains it well.
Note: Don't use the Scale tool at object level, if that's what you used to make it "skinny." Always scale in sub-object mode (Vertex, Edge, Poly), or use the XForm modifier. Otherwise, your model will behave unpredicatably when deforming and animating. If you did Scale at the object-level, make sure to use Reset Xform via Utilities Panel and collapse the stack after. Example: Let's say your Box is 10 x 10 x 10. If you scale at the object level at 50%, Max doesn't know that the Box has been scaled down. It assumes that it's still 10 x 10 x 10 instead of 5 x 5 x 5. To correct this, you will need to use the Reset XForm utility. Or, avoid scaling at the object level.
Attached are based on your last post. I created the box from top view, then I just rotated it on its Z axis.
