no body to help?

Can you clarify which icon you mean?

Is this the Bookmarks Toolbar or the Bookmarks Menu button icon on a toolbar to open a drop down list with the bookmarks or something else?

Note that you only see the Bookmarks Menu button when the menu bar is hidden (View > Toolbars).

You can check for problems caused by a corrupted localstore.rdf file if this is about toolbars or toolbar customization.

• http://kb.mozillazine.org/Corrupt_localstore.rdf

the icon is called bookmarks, it is a button to open a drop down list of bookmarks. it seems that can not put in bookmark toolbar, if you put there, after restart then it is disappeared. in v24 only, so far working fine in V21.

did according to your advise, delete ocalstore.rdf, re-add tool icons, and copy a backup. it works so far. but still do not know why the problem is occur in V24 only.

Hi oldman1881, in a recent version of Firefox (23 or 24, I can't remember), a change was made to the icon. Some users have reported that this caused the icon to disappear. By removing localstore.rdf, you restored the default set of icons.

By the way, by design, the icon that drops down the bookmark menu will be hidden if you re-enable the classic menu bar.