This started with the last 2 or 3 releases of FF. All I get is a blank page. If I close that blank tab or hit the HOME button Speed Dial starts up with no problem. I've checked and I do still have SD set up start up automatically. I've also tried changing the setting to link to a SD bookmark I set up as the home page, but that didn't work either. I switched to Quick Dial for a time and it did the same thing. The developer of that add-on eventually found a bug that was keeping his program from starting up automatically and was able to correct it. But I much prefer Speed Dial to Quick Dial.
Customer support service by UserEcho