I posted this note in misc. help as well but thought I should also post it here since it could really be pertinent to our dynasty challenge.
" Ok, was having several different problems. I moved in the Landgraab family and built my nice, new, large, dynasty house using their funds and household items plus a few of my own. My frig would not allow me to place items in it nor remove items from it. So I tried replacing it with a lower level frig. Everything worked. Then I tried to buy books with their computers and I could not buy anything. I tried clicking on the bookshelves, (theirs), and again could not buy anything. I then tried clicking on the child's bookshelf I had recently bought and could buy books, seeds, etc. So, I believe when you move in another families' household goods they will not work the same as ones you bought yourself. I replaced one of the Landgraab's bookcases and voila, can now buy from that. This may be a bug but I don't know if it is."