Some speed dial extensions require setting your home page to about:blank (or in the Options dialog, "When Firefox starts: Show a blank page"). Is that how this one works? This support article describes some of the reasons that Firefox might lose your settings between startups: [[How to fix preferences that won't save]]. If settings become frozen and unchangeable, check the Windows Control Panel, Uninstall a Program, for something named SearchProtect. This can indicate a malware infection. If you use Advanced SystemCare, it has a number of ways to protect you from changes, including the Surfing Protection feature and one that may replace your settings at Windows boot-up. Check its options thoroughly.