Cleaning a VS2010 WiX Installer project

Question

I have a VS2010 solution with a WiX 3.5 (beta) Votive project, (as well as all the projects for the program that I am installing). When I clean the VS solution all of the program projects get properly cleaned, but the WiX project does not - the wixobj, wixpdb and msi files are not deleted.

So my questions are:

Is what I am seeing expected behavior?

If so what can I do so that these files are deleted when I clean the solution?