I have this problem on Ubuntu 15.04. I had it on previous versions of Ubuntu as well. I did a clean install of 15.04 so the bug is still present in 15.04 (not a remnant of the earlier versions). See attached screenshot. I've seen the missing characters occur in Nautilus and in the gray bar at the top of windows in Ubuntu (e.g., Firefox, gedit, Libreoffice, file download window). On the bright side, it seems to occur less frequently and less severely on 15.04 than in previous versions.
** Attachment added: "Download window with missing characters" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1342675/+attachment/4416511/+files/2015-06-17%2008%3A29%3A41_download-window_missing-chars.png -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1342675 Title: Random characters in screen text suddenly disappear To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1342675/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp