X apps don't launch from Xterm

["Eric d'Alibut" <eric.halibut@gmail.com>]

This is a stable install that has been running, er, with great
stability, for well over a year; it was brought up to date with etch
no problemo earlier in the year. A recent routine 'apt-get update',
'apt-get upgrade' has left me with some new, and rather disagreeable,
behaviour.

This box boots to a command prompt, and then after logging in as a
regular user I launch X with a simple 'startx.' This gets me Gnome. If
I then start an xterm and attempt to launch an X app, such as gqview,
or evince, from the command prompt in that xterm, no app launches;
this is what I get:

--snip--

wingnut@trollboy:~$ gqview
(gqview:26337): Gtk-WARNING **: cannot open display:

wingnut@trollboy:~$ evince
(evince:28047): Gtk-WARNING **: cannot open display:

wingnut@trollboy:~$ echo $DISPLAY
0:0.

--snip--

As you can see, the display id is available in the environment.

Also, setting 'xhost +' in a .xinitrc file does not affect this behaviour.

Has some X policy been put into place? Where to reverse it?


Best,

-- 
No no no, my fish's name is Eric, Eric the fish. He's an halibut. I am
not a looney! Why should I be tarred with the epithet looney merely
because I have a pet halibut?