Hi,
Yeah, try jpeg first, and also i found that you must apply textures to
ALL surface of one component, then you can change the size of that
texture to whatever you want. but i tried just apply texture to one
face of a component, it NEVER works, by applying to all faces it
always works. Also i tried edit component and then apply texture, that
way it won't work as well, you must apply texture, then make to
component or make it component, then apply the whole component.
hope this helps, and if it still won't work, try a new sketchup file.