Created attachment 694810 [details] screen cap showing the problem and my workaround Description of problem: During install I selected Idiom as Brazil and keyboard layout as English (US,International with dead keys), just after reboot I noticed I could not use dead keys. Using sytem settings -> keyboard I saw the only keyboard layout listed is the one I selected during install. Dead keys do not work after selecting it. Adding any second layout, selecting this and then selecting back English (US, International with dead keys) does the magic. Rebooting disable dead keys. I decided to keep two English keyboard layouts on list just for comfort. This way, gnome-shell top bar shows me en1 and if I click over it I can choose en1 or en2. I just choose the same en1 and get my dead keys back. Notice I do not need to choose en2 and back to en1. I just click en1 and it works. I attached a screen cap to make myself clear. In the screen cap I show the layout selector indicating en1. I open gedit and try to use dead keys and it does not work, then I use the selector to select the same en1 and from now on dead keys works until next reboot. I pointed my finger to gdm but I am not sure that is the problem. I just thought the problem appears everytime gnome starts. BTW, ctrl + bkspace restarts GUI and the problem returns. It is not necessary a full reboot. My system is full updated Version-Release number of selected component (if applicable): gdm-3.6.2-5.fc18.x86_64
After my report we had some updates and now the problem is gone. TY for your attention.