Why does my IBook goes missing when I try to look at the books from your stand?

Every time I go toIBooks to buy I have trouble with IBooks which goes back to my books I have already bought, all I want is to find books I want to buy but it just goes back to my library and not to the store, if you look into my site I have about 130 books and still am buying more so even when I have read them I keep in my library to remind me not to buy the same ones or about the author. So is there something I can do to stop keep going around and round till it works and it does not shut down,

Thanks RJB