I use normal windows most of the time; I do not use automatic private browsing, and I haven't tested that mode before replying.

The suggestions in the autocomplete drop-down below the address bar are based on history from non-private windows (as well as bookmarks). If you do a novel search in your private window (novel meaning it contains a unique term that won't match any other history), and then try it in the address bar, it should not be suggested in either a private or regular window.

Do you use any add-ons that modify how the address bar works?

Thanks for reply! I am not using any addons that modify the address bar.

As you say the.. "The suggestions in the autocomplete drop-down below the address bar are based on history from non-private windows (as well as bookmarks)".

What I am seeing though is that the suggestions in the autocomplete drop-down below the address bar include sites that I know I viewed while private browsing, which means the browsing is being stored somewhere and is not truly private.  It would seem that truly private browsing would mean as the private browsing window says "Firefox won't remember any history for this window"  but it is, and I don't know if it's just happening to me, and how to remedy it.

Hi daveb900, if you can spot a pattern to it, that would be helpful, because reports of this seem very rare and without knowing when it happens, it may not be possible to track it down.

Start Firefox in Safe Mode to check if one of the extensions (Firefox menu button/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox menu button/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can check for problems with the places.sqlite database file (bookmarks, history) in the Firefox profile folder.

• Places Maintenance: https://addons.mozilla.org/firefox/addon/places-maintenance/

If the Places Maintenance extension can't repair the places.sqlite database file then remove all places.sqlite file(s) in the Firefox profile folder to make Firefox rebuild the places.sqlite database file from the most recent JSON backup in the bookmarkbackups folder.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file