mckenndk: What does your insurance company think of people coming in to look at things they want to burgle from the property at a later time or when no one is looking.
I would make sure you are covered contents wise as there is usually some ruling that people let into your house are not covered as burglaries.
If there are any extra premiums get them to cover them.
Good queston. I believe that you are not covered (I asked the question when we were selling) as it is the same as a guest stealing from you - those looking through the house have been "invited in" - albeit not by you!
I could be wrong, and it may vary between insurance providers.