Problem with Google search defaulting to address bar

Since updating to the latest version of Firefox I am having problems with the search facility. When I open a new tab it brings up the 'Search with Google' page as usual but as I start typing the text appears in the address box in a tiny font and the 'suggestions' drop-down list completely obscures the Google search box I am trying to type into! Have tried a few different settings but have been unable to change it - this is a problem for me as I wear glasses and need a reasonably large font when searching.