You can try this add-on:

http://yellow5.us/firefox/osb/

This the developer's website of: Organize Status Bar.

When you are in the Customize mode, icons on the Add-ons Bar that are grouped together and covered with a darker box where the "hand" doesn't appear, those are probably old Statusbar icons - the add-on author didn't properly update their extension to the new code for 4.0 extensions for "toolbars". Mozilla included backwards compatibility, but those old icons are "stuck" together. You can try the Organize Status Bar extension to move them around a bit, but from what I experienced you can't move them away from each other. I was only able to re-arrange them within their "own grouping".

Some (possible) bug reports have been filed on the inability to rearrange all of the icons on the Add-on Bar. There may be some involvement of other add-ons causing that problem, but that is yet to be determined.

I have not tried the latest version or Organize Status Bar (OSB) that silkphoenix pointed to in the post above. The note on that page indicates that the only update was changing the <max-version> to 4.0. I had already done that in the previous version of OSB that I have installed and doing just that did not solve the problem. In my case, some of the add-on icons are grouped together with a gray background in Customize mode and those seem unmovable.

To move items to the left, you can try inserting Flexible spaces (or spaces) from the Customize palette.

Other issues needing your attention

The information submitted with your question indicates that you have out of date plugins with known security and stability issues that should be updated. To see the plugins submitted with your question, click "More system details..." to the right of your original question post. You can also see your plugins from the Firefox menu, Tools > Add-ons > Plugins.

• Adobe Shockwave for Director Netscape plug-in, version 11.5.9.615
  • Current security update version is 11.5.6.620
• Adobe PDF Plug-In For Firefox and Netscape "9.4.2"
  • Current security update versions are 9.4.3 and 10.0.2 released on 2011-03-21
• Shockwave Flash 10.2 r152
  • Security update version10.2 r153 released on 2011-03-21

1. Check your plugin versions on either of the following links':
   • http://www.mozilla.com/en-US/plugincheck/
   • https://www-trunk.stage.mozilla.com/en-US/plugincheck/
   • Note: plugin check page does not have information on all plugin versions
2. Update Shockwave for Director
   • NOTE: this is not the same as Shockwave Flash; this installs the Shockwave Player.
   • Use Firefox to download and SAVE the installer to your hard drive from the link in the article below (Desktop is a good place so you can find it).
   • When the download is complete, exit Firefox (File > Exit)
   • locate and double-click in the installer you just downloaded, let the install complete.
   • Restart Firefox and check your plugins again.
   • Download link and more information: http://support.mozilla.com/en-US/kb/Using+the+Shockwave+plugin+with+Firefox
3. Update Adobe Reader (PDF plugin):
   • From within your existing Adobe Reader (if you have it already installed):
     • Open the Adobe Reader program from your Programs list
     • Click Help > Check for Updates
     • Follow the prompts for updating
     • If this method works for you, skip the "Download complete installer" section below and proceed to "After the installation" below
   • Download complete installer (if you do NOT have Adobe Reader installed):
     • SAVE the installer to your hard drive (save to your Desktop so that you can find it after the download). Exit/Close Firefox. Run the installer you just downloaded.
     • Use either of the links below:
       • https://support.mozilla.com/en-US/kb/Using+the+Adobe+Reader+plugin+with+Firefox (click on "Installing and updating Adobe Reader")
       • Also see Download link': http://get.adobe.com/reader/otherversions/
   • After the installation, start Firefox and check your version again.
4. Update the Flash plugin to the latest version.
   • Download and SAVE to your Desktop so you can find the installer later
   • If you do not have the current version, click on the "Player Download Center" link on the "Download and information" or "Download Manual installers" below
   • After download is complete, exit Firefox
   • Click on the installer you just downloaded and install
     • Windows 7 and Vista: may need to right-click the installer and choose "Run as Administrator"
   • Start Firefox and check your version again or test the installation by going back to the download link below
   • Download and information: http://www.adobe.com/software/flash/about/
     • Use Firefox to go to the above site to update the Firefox plugin (will also install plugin for most other browsers; except IE)
     • Use IE to go to the above site to update the IE ActiveX
   • Download Manual installers.
     • http://kb2.adobe.com/cps/191/tn_19166.html#main_ManualInstaller
     • Note separate links for:
       • Plugin for Firefox and most other browsers
       • ActiveX for IE

the edmeister

Thanks for that info about the "old" Status Bar buttons being a possible problem. I had not seen that info before.