Virtual Copies disappearing/not appearing

[Lyle157F]

The problem I'm having is that my virtual copies just randomly disappear. I will be in a collection and the virtual copies show up with the little turned up bottom left corner. Then a few days later, they are all gone? I haven't moved anything, they just disappear? Turning the filters off/on doesn't help at all.

[dj_paige]

Smart Collection? Or regular Collection?

Have you tried changing the sort order of the collection to see if that is the problem?

Please provide the following basic information:

[TheDigitalDog]

Odd, any chance optimizing the catalog or resetting your preferences makes a difference? 
I've never seen this issue. What OS?