Have you considered setting your own Homepage, and not using about:home?

http://support.mozilla.com/en-US/kb/How+to+set+the+home+page

Another option is use a password for your Logon User Account in Windows, and setup a "guest" Logon User Account for other people that you might allow to use your PC.

Thanks dude , Done.

You're welcome.

Please click the Helpful button next to the answer that solved your Firefox support issue, when you are logged in, so this thread gets marked as Solved.

Be aware that that feature can still be accessed via History > Restore Previous Session or Recently Closed Windows or Tabs.

If you leave windows open then you might consider to not save cookies from those open tabs.

You can set the pref browser.sessionstore.privacy_level to 2 on the about:config page to disable saving cookies via session restore.

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.

Thanks guys...fixed. However Mozilla should never have had this flaw. What if somebody was doing internet banking and was not aware of how passwords can be bypassed. Thousands of dollars can be stolen due to Mozilla's negligence.

Food for thought for the Mozilla guys....

Hmmm... When I click Logout on my bank's web site, no amount of hitting Back or reloading the page/tabs will make it think I'm still logged in.