Not All Objects in Group Appear in Preview Mode

Hi again-

I have run into a rather frustrating issue. I'm using groups and action groups to create my elearning title. For one of the groups, the next and back buttons do not show up in any preview mode, be it in the title itself or when previewing on the web. These two buttons are checked as "Always on top" and have NOT been checked as "Initially hidden." I've tried changing their order in the group, and deleting and reinserting them, but nothing I do makes them show up. Here is a screen shot in edit mode:

[ATTACH=CONFIG]613[/ATTACH]

What am I doing wrong?

Thanks-

Pamela