These should be moved to the Gallery, because you're no Newbie! Nice work.
P.s.
that man standing in the living room should be made into a "Face Me" component.
Hi Hector and welcome!
This is called "clipping" and a good wealth of things can cause it. Review this "list" and check your model if any of the reasons (or fixes) may apply http://support.google.com/sketchup/bin/answer.py?hl=en&answer=36261