Even better just disable session restore entirely - Browser.sessionstore.enabled - Since Firefox 3.5 this preference is superseded with setting browser.sessionstore.max_tabs_undo and browser.sessionstore.max_windows_undo to 0.
As I understand this feature is there so if the browser crashes it can restore your windows and tabs - I don't remember having a browser crash on me since the demise of Flash.
As I understand this feature is there so if the browser crashes it can restore your windows and tabs - I don't remember having a browser crash on me since the demise of Flash.