For whatever reason they decided to break window buttons in the gnome GUI for Ubuntu 10.4. I dual boot Windows and Ubuntu and can’t be bothered to have such inconsistencies. Here’s how to “unbreak” this.
push Alt+F2
type ‘gconf-editor‘ without quotes, push enter
go to apps->metacity->general->button_layout
delete the old value field, replace it with this: menu:minimize,maximize,close