Dan,
Welcome to Apple Discussions.
Quit System Preferences if it's running and trash the following files:
/Users/yourusername/Library/Preferences/
com.apple.systempreferences.plist
/Users/yourusername/Library/Preferences/ByHost/
com.apple.systempreferences
/Users/yourusername/Library/Caches/
com.apple.preferencepanes.cache
Then log out/in or restart and check System Preferences for proper functionality. Let us know what happens.
;~)