It's much simpler to use the Stylish extension instead of userChrome.css.

• https://addons.mozilla.org/firefox/addon/stylish/

After installing it, open the Add-ons Manager, User Styles cateogory. Click the Write a New Style link at top. Paste your CSS code there, and click the Preview button to see what the changes look like. Click the Save button if you're happy with the result.

If you only want to remove icons from the Bookmarks Toolbar — which is what the Bookmarks Deiconizer extension used to do — then this is the CSS code to use:

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

#PlacesToolbarItems > .bookmark-item > .toolbarbutton-icon {
  display: none !important;
}

#PlacesToolbarItems > .bookmark-item > .toolbarbutton-menu-dropmarker {
  display: -moz-box !important;
}

If you insist on userChrome.css instead of Stylish, see the instructions below.

• http://kb.mozillazine.org/UserChrome.css

Keep in mind the following:

• The file name is case-sensitive: userChrome.css
• The file extension is .css — you may need to display file extensions in Windows to avoid naming it .css.txt by accident.
• Firefox must be restarted for changes in userChrome.css to take effect.

I wasn't aware of that particular extension. I got the extension, used your code, and I added some margins on either side.. and it was perfect!

Thanks!

Gingerbread_man's script did not work for me but this one did (from here: http://forums.mozillazine.org/viewtopic.php?f=38&t=675505&start=0&st=0&sk=t&sd=a.)

___________________________________________________

#urlbar > #urlbar-icons > #star-button
{
display: none !important;
}

____________________________________________________

Note: I am using Firefox 16 and Palemoon 12 though.