My keyboard loses functionality when I try to leave comments on Facebook. Delete, backspace, apostrophe and cut, copy and paste are disabled. This only happens in comments, no functionality is lost in messaging or status updates. I have disabled all my add-ons and restarted Firefox and the issue persists. I have updated add-ons, restarted Firefox and the issue persists. I have updated Firefox and that made no difference. I have cleared cookies and cache and still no luck. SOLUTION: I disabled the Grammarly Lite add-on and this seems to have resolved the issue. I have informed Facebook of the issue. I cannot find any information about this problem in Facebook's troubleshooting. I cannot replicate this issue in Internet Explorer. All the functions work fine. I have the same issue on a different device that runs Windows 7 Starter and on a laptop that runs Windows 8.1.