Hello,

This seems like issue with your cookies. My add-on is using cookies to keep you logged in.
See the Firefox Options page (about:preferences) and on the tab "Privacy & Security" check the Cookies settings and also History.
If you set it up to Remember history and "Accept cookies and site data from websites (recommended)" with "Keep until - They expire" then it should work.
Also if you are using some tool (or add-on) to block cookies, make sure to add exception for domain "group-speed-dial.fastaddons.com".

Let me know to my support e-mail if this didn't helped.

Best regards,
Juraj Mäsiar