Have 2 folders of pictures with one set @ small thumb view and the other on big thumbs view.
Go to a picture in the Big thumbs folder
Open it full screen (enter)
press X to go back to gui
Navigate up one folder using the icon in the thumbview for this (1st entry in the list)
go to the folder which has small thumbs
Now you will see only 9 small thumbs.

This will NOT happen when you will not show a pic full screen in the big thumbs folder.