I filed a Mozilla bug report about this here: https://bugzilla.mozilla.org/show_bug.cgi?id=1204694
I also created a video showing how I can reproduce this bug every time in Thunderbird: https://youtu.be/ybkVPSfiNJs The bug seems to be related to the spell-check-as-you-type feature, but may be related to the graphics driver as well, as the bug occurs on my laptop (Radeon open-source drivers) but not my desktop (NVIDIA proprietary drivers). More info can be found in the bug report I linked above. ** Bug watch added: Mozilla Bugzilla #1204694 https://bugzilla.mozilla.org/show_bug.cgi?id=1204694 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1301225 Title: Parts of Text disappear in Firefox and Thunderbird Editors /Text Areas Status in firefox package in Ubuntu: Confirmed Status in thunderbird package in Ubuntu: Confirmed Bug description: System info: Firefox 28 Thunderbird 24.4.0 Ubuntu 13.10 64 bit When I edit text in Firefox or Thunderbird, parts of this text (usually entire rows above the cursor) seem to disappear while I type. This happens e.g. when I edit an email message inThunderbird, or edit a Jira comment or a Wikipedia page in Firefox. Sometimes the 'opposite' happens, i.e. a row is copied, so it is shown twice. The text is not really gone; I can restore it by selecting it (e.g. with Ctrl-a). I.e. only the text display is affected. The behavior is not quite reproducible. It does happen frequently, but I can't reproduce it exactly by typing the same text again. I had never observed this behavior before the latest Firefox upgrade. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1301225/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
