When duplicating a group of cell styles, the resulting duplicate group's name is appended with " copy" but the style names contained within that group folder are not appended with " copy" and therefore you have duplicate style names in the Cell Styles. Additionally, when duplicating more than one style within a group, sometimes multiple "copy" styles are created, and other times, they are not, rather, the edit style dialog box appears...but on save, no style is saved into the group. Seems a bit kluge.