Speed Dial doesn't load automatically on Firefox startup

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.