Hello Tasha.

No, your Firefox is up to date. This is either a bug, or something has gone wrong with your installation of Firefox. I suggest you try to run Firefox in safe mode to see if you still have the same issue. If you do, try disabling one extension at a time to see which one is causing the issue. Once you find it, disable it for good and contact its author for support.

If safe mode has the same issue (or if disabling extensions doesn't help), please say so.

Do you mean bookmarks on the Bookmarks Toolbar or icons on other toolbars like the Navigation Toolbar?

If the favicons from bookmarks disappear then make sure that you are not in Private Browsing - Use Firefox without saving history mode and use Delete browsing, search and download history on Firefox to clear the Browser Cache. You are in Private Browsing mode if you see "Tools > Stop Private Browsing".

I have the exact same problem on Windows 7 Home Premium x64. A reinstall of Firefox and Thunderbird brings them back, but after a while, they go away again.

Private Browsing and Clearing Recent History does nothing to change it. Attached is a screen shot of the Start Menu, but it happens on the taskbar and in folders.

also running FF 3.6.3 under XP

This happens to me too but in the Bookmarks Toolbar. Out of 15 or so Favicons I have on the Bookmarks Toolbar four or five disappear (pictures are gone but gray outline still remains with text, see accompanying pictures) each time I close Firefox 3.6.3 in Windows XP. If I visit the site the favicon pictures are restored, until I close the Firefox. Any suggestions. Thanks.

a.png: Disappeared favicons with gray outline along with non disappearing favicons b.png: Restored favicons after visiting all the sites.

My browser is showing text where the icon and text was. So I went to View -Toolbars- then customize and under this box that is brought up. AT the bottom click show and pick icons and text.