Bug with hirizontal panel

[nxhoaf]

Hi there,
I've just installed Ubuntu11.04, As I'm familiar with vertical panel, I changed the horizontal panel (the default one) to the vertical. But it seems not to work with me. And here is the bug:
http://www.youtube.com/watch?v=6Gc0gk5_c9U
Can anyone tells me how can I fix it ?

[Frogs Hair]

Is this in Classic Ubuntu with or have you disabled Unity enabled the gnome panel in Unity ? If using Classic Ubuntu try the following command to reset the panel .
gconftool --recursive-unset /apps/panel && killall gnome-panel