There is no difference between tho two names, they both refer to the sync key that is used to encrypt data locally before sending it to the sync server. Try to create a new profile as a test to check if your current profile is causing the problems. See "Creating a profile": *https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles *http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues If the new profile works then you can transfer some files from an existing profile to the new profile, but be careful not to copy corrupted files. *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I will try this, but can I sync my notebook, laptop and desktop all at the same time?

Sure, there shouldn't be a problem to add other devices once you have created a Sync account. *https://support.mozilla.org/kb/how-do-i-set-up-firefox-sync *https://support.mozilla.org/kb/add-a-device-to-firefox-sync ---- *https://support.mozilla.org/kb/how-do-i-manage-my-firefox-sync-account *https://support.mozilla.org/kb/firefox-sync-troubleshooting-and-tips