TO FIX THE PROBLEM, I went back to version 1.1.6 which also uses the older detection algorithm and that works great for me (five stars great). Other users may want to do the same until the bugs are worked out of the latest release. On the options page for this extension, I set "Allow automatic updates" to OFF since I don't want 1.1.6 to be replaced by that buggy new version. Once the bugs are fixed, I'll set it back to the Default value again.

The older 1.1.6 version was obtained by going to the bottom left side of the Firefox Add-On page for this extension. You see a clickable link to See All Versions.