Hi,

I'm very new to Sketchup and have been learning by following the tutorials given in 'Drafting and Design for Woodwoorkers'. I think my problem is pretty simple, but have struggled to articulate due to my unfamiliarity with the correct terminology. To help you help me I have produced a short video of the problem that I am encountering (http://www.youtube.com/watch?v=lw9EHyYyP4g). Hopefully, alongside the explanation I am about to give, someone will understand what I'm getting at.

In short, I want to create 3 solid and independent components: two legs, with an apron between them (the project is one side of a small table). When I say independent what I mean is that moving one component won't affect the other two. However if you look at the video (or just skip to 1:04) you can see that when I move the apron, not only is the end of the apron 'hollow', but I am also left with two 'holes' in the legs where the apron was previously. Can anyone tell me what I'm doing wrong?