I am not sure what was going on there (unless it is also combined with some graphic display issue) but you should carefully follow a very important rule in Sketchup: never put raw ("primitive" or ungrouped) geometry on any other layer than Layer0. What's more (especially while you are getting familiar with the program), never even change the default layer to anything else than Layer0. Layers in SU do not separate geometry just control visibility. This also means that while drawing on one layer, you constantly merge with geometry on another layer or when you move something, "sticky" geometry will also me moved with it. Here is a good video demonstrating it: YouTube - Google SketchUp Technique Series: Layers [flash=480,385:15bruc50]http://www.youtube.com/v/fBdP499iw0Y?fs=1&hl=en_US[/flash:15bruc50] As the video also demonstrates, use group/components to separate geometry.