Did you check that you haven't set the pages as multiple home pages? ---- See these articles for some suggestions: * [https://support.mozilla.com/kb/Firefox+has+just+updated+tab+shows+each+time+you+start+Firefox Firefox has just updated tab shows each time you start Firefox] * [https://support.mozilla.com/kb/How+to+set+the+home+page How to set the home page] - Firefox supports multiple home pages separated by '|' symbols * http://kb.mozillazine.org/Preferences_not_saved

yup, i'v checked it double times now

Did you check http://kb.mozillazine.org/Preferences_not_saved ? ---- It is also possible that there is a problem with the files [http://kb.mozillazine.org/sessionstore.js sessionstore.js] and sessionstore.bak in the [http://kb.mozillazine.org/Profile_folder_-_Firefox Profile Folder] Delete the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder. * Help > Troubleshooting Information > Profile Directory: Open Containing Folder * http://kb.mozillazine.org/Profile_folder_-_Firefox * http://kb.mozillazine.org/sessionstore.js If you see files sessionstore-##.js with a number in the left part of the name like sessionstore-1.js then delete those as well. Deleting sessionstore.js will cause App Tabs and Tab Groups to get lost, so you will have to create them again (make a note). See: * http://kb.mozillazine.org/Session_Restore