On further investigation, it seems to have something to do with the fact that R20 now has a built-in option to export only the selected object in the scene.
And as you know, CV-Smart Export also has an option to export only what is selected.
If I have the Selected Only option unchecked in the settings for CV-Export, it will rename my scene file when it exports.
But if I check the Selected Only box in CV-Export settings, it then exports nothing!
(That is when the built-in FBX export preference in C4D is set to export only what is selected. “Selection Only”.)
I’ve only tested this with the FBX format.
I’m using the latest version of CV-Export.