Gnome screen shifted up on Dell Inspiron

["Mauricio" <mcornejo@iso.com>]

I've just installed Debian's "Sarge" distribution on a Dell Inspiron
3800 and the display is shifted up by about a quarter of an inch (6mm)
so that I only see about half of Gnome's control bar (I don't know it's
proper name) at the top of the screen.

The keyboard does not have any controls for horizontal/vertical shifts.
 The computer's user manual does not mention such shifting either.

Any ideas on how to fix it?  Thanks in advance for any suggestions.