Context: SUSE 12.2, kde 4.8.4. Selected "Different widgets for each desktop" from Virtual Desktops and all of my desktop icons disappeared, turned it off and everything returned to the previous setup. Tried different things and, along the way, I got different wallpapers per desktop and had my icons on desktop 1 but not in their original positions (moved them to resolve that), how I got there is not known.

Now I want icons on other desktops but noticed that, only on 'desktop 1', do I have the menu with 'Create New' on it. Having almost destroyed my 'desktop 1' configuration by trying things on other desktops (changing the highlighted activity), I'm apprehensive about further experimentation.

This leads me to ask where the settings are kept for multiple desktops. I have *.desktop files in my ~/Desktop directory and I have found plasma-desktop-appletsrc and plasma-desktoprc but i don't know if there are more files to consider or how changes in those files affect the desktop. If someone can point me to a source explaining all of this I will be glad to do the reading but haven't been able to find this so far. Otherwise, any postings with partial explanations would be appreciated. Thanks for any and all help.

It seems that on "Desktop 1" you have set the layout to "Folder View" where as the other activities are still likely using the regular "Desktop" layout.
The different wallpapers, layouts, icons, etc appearing on the Desktop is part of KDE functionality known as "Activities".