Under desktop settings I can't get the cycleing of background pictures in a folder to work properly. It would change once and then not work again.
Do you mean automatic cycling through desktop images every so many minutes? If so, try this:
1. In desktop settings, select "Image List" and add your images to the list.
2. Create the following crontab entry:
*/5 * * * * DISPLAY=:0.0 xfdesktop --reload > /dev/null 2>&1
...change the "5" in the first field to be the amount of minutes you want to elapse before the image is switched.
If you mean something else, can you explain exactly what you're looking to accomplish?