HOWTO: Restore Firefox 4 context menu option order
Published on 2011/07/13 by Igor Levicki
Someone "smart" at Mozilla Corporation decided that instead of rolling up the sleeves and fixing that 10 year old bug with application shortcut keys not working when there is a plugin on a web page they should fiddle with reversing the order of "Open Link in New Window" and "Open Link in New Tab" context menu entries. Obviously, they never heard one of the most basic UI design rules — do not move things around with each new software release.
If you spend a lot of time using your computer you most certainly get used to certain things being in certain positions and this change is throwing you off and slowing you down. Solution is simple, just create userChrome.css in %USERPROFILE%\AppData\Roaming\Mozilla\Firefox\Profiles\YOUR_PROFILE_FOLDER\Chrome (where YOUR_PROFILE_FOLDER looks like acde3ij5.default) with the following content:
#contentAreaContextMenu > * { -moz-box-ordinal-group: 2; } #context-openlink { -moz-box-ordinal-group: 1 !important; }
Problem solved.