One possibility is that those buttons are created by an extension, such as an add-on toolbar.

Since extensions are deactivated in Firefox's Safe Mode, you could check whether they go away in Safe Mode. More info: Diagnose Firefox issues using Troubleshoot Mode.

You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

Any difference?

Can you attach a screenshot?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

• Use a compressed image type like PNG or JPG to save the screenshot
• Make sure that you do not exceed the maximum size of 1 MB

Did you verify that this aren't bookmarks?

• https://support.mozilla.org/kb/how-do-i-use-bookmarks

Your System Details shows

Installed Plug-ins

Adobe Shockwave for Director Netscape plug-in, version 12.1.3.153 Adobe Shockwave for Director Netscape plug-in, version 12.0.9.149 Adobe Shockwave for Director Netscape plug-in, version 12.0.7.148 Adobe Shockwave for Director Netscape plug-in, version 12.0.5.146

Having more than one version of a program may cause issues.