There has been a bug in Firefox for a long time that causes Copy / Paste to work inconsistently on Windows. Recently this bug has been driving me mad. After doing a little investigation I hear this bug is supposedly fixed in the soon to be released Firefox 220.127.116.11.
If you have a look here you will find there's a 18.104.22.168 update pending. The update comes in the form on a .mar patch file. You can manually install the patch by doing the following (instructions found here).
- Make a folder "c:\firefox-update"
- Copy updater.exe, updater.ini and the "updates" folder from firefox into your new folder (c:\firefox-update)
- Download the .mar-file to c:\firefox-update
- Rename the .mar-file to "update.mar"
- Start a command prompt (start->run->cmd)
- Browse to your firefox-directory (c:\program files\mozilla firefox)
- Make sure Firefox is closed
- type: "c:\firefox-update\updater.exe c:\firefox-update 0" (a progress indicator should appear)
- Hit enter
- Start firefox and it's updated
I have just upgraded to Firefox 22.214.171.124. Please comment here if you find this does/doesn't fix it. Fingers crossed!