There are two places that you can add third-party System Preference sections:
/Library/PreferencePanes/ - these show up under "Other" and are available to all users
~/Library/PreferencePanes/ - these also show up under "Other", but are only available to the user who installed them (it will exist in their Library folder)
Now how the Keyboard pane got in Other, I'm not sure. Check to see if anything is in the folders listed above, but my guess is no. One other place you can check is:
/System/Library/PreferencePanes/
This might contain your duplicate items...if it does, you will most likely need to delete one through the terminal. But be very, very careful...if you delete the wrong one, you may lose your ability to modify preferences for that section. I don't recommend doing that unless you know what you're doing.