I have exactly the same problem

Same thing, only started happening after the 3.6.6 update.

I have the same problem. Running v3.6.6 on Ubuntu Lucid v10.04. Made a new profile and problem persists. ~~~ 0;-Dan

If you use Delete browsing, search and download history on Firefox in Firefox 3.5/6 or Clear Private Data in Firefox 3 to clear the 'Browsing History' when Firefox is closed then restoring tabs from the last session (e.g. "Save & Quit" or "Show my windows and tabs from last time") doesn't work.

This is not a solution, nor a work-around. The only thing this points out is where the problem lies. Settings are meant to be used in all sessions, barring exceptions and the fact that Firefox asks if you'd rather SAVE and then quit, makes it an exception. The user has elected to skip the clear browsing history step.

However, if the settings are permanently changed as you suggest, then the history will always be remembered for eternity when Firefox is closed. You then have to manually clear your history first at every session before closing.

Older versions of Firefox never behaved in such manner and recognized that the Save and Quit superseded the setting to Clear History.