Has your home page changed to something else? Sometimes knowing what appears on the home page is helpful to disabling an add-on or removing a problem setting.

You can check the setting here:

orange Firefox button or classic Tools menu > Options > General

Any additional info you could provide would be helpful.

home page is mozilla but I do not see mozilla toolbar / correct homepage link to search . I think I do not have what you mentioned. should look like : http://blog.mozilla.org/ux/2012/05/update-on-firefox-13s-home-and-new-tab-redesign/firefox-beta-13-new-tab/

The page with the nine thumbnail images of recently visited sites usually appears when you open a new tab (e.g., Ctrl+t). Over the years, before this feature was added to Firefox, there were many add-ons that created similar pages. If you used one of these add-ons and it stopped working, it might need to be updated or replaced.

You might also be able to use the built in new tab page as your home page if you like by changing your home page to about:newtab. I haven't tested how well that works.

Does that get you any closer to a solution?

If not, perhaps you could post a screen shot of what your Firefox looks like. This article has some tips on that: How do I create a screenshot of my problem?