I don´t know how to avoid that by shure, but I know it happens when the basic layer is empty, not a moveable layer, or is an animation set. So maybe if you avoid that you can avoid the bug.
P.S. Cliff, this section is a great idea! Generally I like the new sectioning of this forum in the well chosen categories!
![Smile :)](./images/smilies/icon_smile.gif)