You can check for problems with the places.sqlite database file (bookmarks, history) in the Firefox profile folder.

• Places Maintenance: https://addons.mozilla.org/firefox/addon/places-maintenance/

If the Places Maintenance extension can't repair the places.sqlite database file then remove all places.sqlite file(s) in the Firefox profile folder to make Firefox rebuild the places.sqlite database file from the most recent JSON backup in the bookmarkbackups folder.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

Start Firefox in Safe Mode to check if one of the extensions (Firefox menu button/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox menu button/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Nothing is helping, I come to the conclusion that this is a problem with FF41, pity I like the rest of FF41, but this is highly irritating and I will have to return to FF26

Going from Firefox 26 all the way to Firefox 41 is a big jump due to major changes made to Firefox in between those two versions. If anything, Firefox 41 is working better for users when switching tabs than the old Firefox 26 version worked.

Try a new Profile and see if that problem is eliminated. https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If your problem is solved, see this KB article to learn how transfer your data to the new Profile. https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Also, make sure you update your Plugins - Shockwave Flash 17.0 r0 is an old version and no longer secure.