fedora f12/gnome, "Gtk-WARNING **: cannot open display" on workspace 2

[Dale Dellutri]

I'm using workspace 2, and I'm trying to open some applications to
be displayed on workspace 2.  gedit works properly whether I start
it from a terminal command line or from the Applications menu.

Gsview will start and work properly if I start it from the Applications menu:
  Applications -> Graphics -> Gsview
but it fails with the "Gtk-WARNING **: cannot open display" message if
I try to start it from a terminal command line:
  gsview something.pdf &

Is this a bug in Gsview?

If I try to open Adobe Reader from the Applications menu
on workspace 2:
  Applications -> Office -> Adobe Reader 9
it leaves a pulsing "Adobe Reader" indicator in the bottom
status bar, and if I click it, I get switched back to workspace 1.

Is this a bug in Adobe Reader?

If I try to start it from a terminal command line:
  acroread something.pdf &
it fails with the message:
  Gtk-WARNING **: cannot open display

Is this another bug in Adobe Reader?

Shouldn't these applications all work like gedit?

--
Dale Dellutri