Even more funny, with kernel 3.17 Firefox stopped hanging the on the page I have linked above http://www.howtogeek.com/196655/how-to- configure-the-grub2-boot-loaders-settings/ (on kernels starting from 3.18-rc1 the whole application would hang after few seconds during loading this page).
This looks like offtopic, but probably would help to track the original problem. I would think of a hang/freeze problem in some kind of messaging subsystem inside the kernel, which would give unpredictable random hangs in visually different and absolutely non-connected parts of the system (firefox/keyboard switcher,MTP/ADB devices). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1314556 Title: Unable to mount Android MTP device To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gvfs/+bug/1314556/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs