Hello Christian.

If it was the Bookmarks toolbar and it's no longer visible, you can make it visible by going into View > Toolbars > Bookmarks Toolbar.

If the Bookmarks toolbar is visible but no bookmarks are displayed, go into Bookmarks > Bookmarks Toolbar and see if there's anything inside it. If there is, go into View > Toolbars > Customize... > Restore default set, to restore your interface buttons to their default postion. If there is nothing inside Bookmarks > Bookmarks Toolbar, something deleted what was inside it. You should be able to restore your bookmarks by going into Bookmarks > Organize Bookmarks... > Import and Backup > Restore.

If none of this helps, you may be having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal?

Whenever you have a problem with Firefox, whatever it is, you should make sure it's not coming from one of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in safe mode and select Disable all add-ons. If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See this article for information about troubleshooting extensions and theme. You can troubleshoot plugins the same way.

If you want support for one of your add-ons, you'll need to contact its author.

On firefox 5 the quick links are gone too.

dang. I made a not so nice post earlier., and deleted it. Google is to blame I think. The "quick links" are also poof on firefox 4 when disabeling the google toolbar.

So, I wait for google to update their toolbar before I update firefox.