Every time I minimize firefox it disapears? then I cant maximize it again without restarting it? Im using ubuntu!
If you deleted one of the kicker panels in Gnome it must of been the one with the Window List notification area, if so right klick on the kicker panel> Add to Panel> Window List.
you can use Alt-Tab to get a window back too, and maybe even the windowskey-tab too if you have that shortcut with compiz http://en.wikipedia.org/wiki/Alt-Tab