Choosing a bookmark from the dropdown occasionally sends me to a link from the page I am on, as if the bookmark drowpdown is not even there.

On my new dell laptop, Firefox seems to run well. however, when I select one of my regular bookmarks from the dropdown, it ignores the choice and chooses a link (e.g. a news story) from the page I'm currently on, one directly under the bookmark I've chosen. If I choose the bookmark link again it operates correctly.