The cam2pc Image Browser is only able to show pictures located on your computer (or through the network). Therefore once you have archived some pictures on a CD or a ZIP disk and removed them from your computer, cam2pc is not able anymore to show them to you.
These images are so-called Offline contents. With this feature cam2pc is able to show you the thumbnails of your archived images. After having created a new CD and removed the images from your hard disk, go to the Tools menu and choose Catalog Images. Change the directory to be your CD-ROM drive and click the Start button. At the end of the process you can safely remove the CD or ZIP from its drive.
When you are done, close the dialog and check the "Offline contents" item in the tree (it should be the last item so scroll down if needed). Expand this item and you should see your CD listed under the name you gave it when burning it. If you expand the CD you should see all the folders located on your CD and if you select one of them you should see thumbnails for all the images located on your CD. And this without having to insert the CD in the drive!
Of course there is not much things you can do because cam2pc only stored thumbnails of the pictures and not the pictures themselves so you do not have access to any of the features that modify pictures (plus the fact that a CD is generally read-only). But if you want to see one of these images fullscreen then cam2pc will prompt you to insert the right CD and can start a slideshow for instance as soon as the CD is inserted!