When you insert a Standard Object onto a master slide and then apply the master slide to a Filmstrip slide, the Standard Object on the master slide appears on the Filmstrip slide(s). You can see the Standard Object, but you can't select it or edit it. In my Captivate classes, I describe the relationship between objects placed on a master slide and a Filmstrip slide this way: it's as if a piece of plexiglass has been dropped on top of the Filmstrip slide that protects the master slide objects. You can click on the object on the Filmstrip slide, but you can't pass through the plexiglass and select the object.
If you want to move, delete, or otherwise edit an object that has been placed on a master slide, you have to edit the master slide. Once you have edited an object that is on a master slide, the change instantly affects every Filmstrip slide that is using the edited master slide.
The problem with adding objects to a master slide is that pesky plexiglass effect. What if you need to design a master slide for a fellow developer that includes a placeholder for an image? If developers use your master slide, they'll be able to see the placeholder, but they won't be able to select it and replace it with an actual image. Without the ability to select placeholder objects, there's really no value in the placeholder.
But wait... there is actually a placeholder feature in Captivate that you've likely missed. If you're working on a master slide and visit the Insert menu, you'll see a Placeholder Objects menu item. (Many folks miss the Placeholder Objects menu item because it is only visible when you're actively working on a master slide.)
Insert a Placeholder Object on the master slide as you would any Standard Object. Then, on the Filmstrip, apply the master slide to the Filmstrip slide via the Master Slide drop-down menu on the Properties panel.
Once you have applied the master slide to the Filmstrip slide, you'll be able to select and edit the Placeholder Object directly on the Filmstrip slide. For instance, I inserted an Image Placeholder Object on my master slide. Then, from the Filmstrip slide, I was able to select the Image Placeholder Object, insert an image, move the object around my slide and re-size it.
Best of all, I was able to reset the slide. After inserting an image into the Placeholder Object, I accidentally re-sized and moved the object from its original master slide position. Instead of re-resizing and dragging the object back to its original position (or using the Undo command multiple times), I simply clicked the Reset Master Slide button (shown in the image above), and the object instantly returned to its master slide size and position--on its own. This is an awesome, often overlooked, feature!
If you'd like to see a demonstration of how to create and use a master slide (and how to use a Placeholder Object), check out this video on the IconLogic YouTube channel.