In the process of setting up a sample file to post, I figured this out!

When I defined the menus in the Custom UI Editor, I included "itemsize=large" in some of the menus (it must have been in the code I copied from a sample template I used). In some other menus I didn't include it (because it wasn't included in the sample code I used for those).

If itemsize is set to "large", I will get more spacing between the buttons, even if the button text is only 1 line. If I leave itemsize out, the size is "normal" and the buttons will appear closer together.

I also figured out that if I've included descriptions for the buttons but don't set itemsize to "large", the descriptions won't show. That did happen to me as I was setting up the ribbon code and I had no idea what I had done, so I started that menu over by copying code that looked right and changing the text.

Cheryl