I have Firefox v38.0.5 (latest) installed on Windows 7 SP1 32-bit. The NS version is v22.5.0.124 (latest). Norton Toolbar version is v2015.5.0.111. No other Norton addon is installed in Firefox.
When I try to activate Identity Protection for the first time, it shows me that Firefox is not installed. IE option works however.
I have even tried running the Get Support option on icon right click, but no effect.