Thank you guys.

Well, my first idea was to cut the solid and erase the "bad" part, and then make a simetry. ;-)

By the way, I had forget a cuestion.

If you see my screenshots, you´ll can see that I´ve lost the small arrows that let me to work in a full screen, overlaping the taskbar.
My browser is firefox 3. If I open MoI like and Admin (I ususally work like an user with a limited account) those arrows appears.
Dou you know what happens?

Thank you again!