There is an unofficial GUI tool that allows to change this and other settings: http://marianochavero.wordpress.com/2011/04/20/a-simple-gui-for-unity-2d-settings-ubuntu-11-04/
Alternatively, you can change that from the command line, just issue the following two commands in a terminal:
gconftool-2 --type=int --set /desktop/unity-2d/launcher/hide_mode 0 gconftool-2 --type=bool --set /desktop/unity-2d/launcher/use_strut true
There is an unofficial GUI tool that allows to change this and other settings: http:// marianochavero. wordpress. com/2011/ 04/20/a- simple- gui-for- unity-2d- settings- ubuntu- 11-04/
Alternatively, you can change that from the command line, just issue the following two commands in a terminal:
gconftool-2 --type=int --set /desktop/ unity-2d/ launcher/ hide_mode 0 unity-2d/ launcher/ use_strut true
gconftool-2 --type=bool --set /desktop/