Problem with Orca

[Alain Joly]

Hello all,
I would like first apologize if I sent a message to the wrong list.
I'm French and I have perhaps not understood the real subject of this list.
Please, if I'm wrong, could you give me a mailing list where I couldsubscribe ?
For now I will try to quickly explain my problem.
I'm a new Ubuntu user and also a new linux user.
My configuration :
Ubuntu version : 8.04 Hardy Heron
Mother board : Asustek
video : NVIDIA 128 Mb
RAM : 1.5 Gb
CPU : pentium 4 3.2 GHz

My problem :
In general, I cannot access to the different gnome desktop utilities because, when the software is launched and when the window is opened, orca doesn't to speak any more.
For example : the window connexion (menu System/Administration/window connexion)
Orca speaks and I can choose a menu. Then, when the window is open, Orca no longer speaks. When I close the window with "ctrl-F4, Orca speaks again.
I've tried with other desktop utilities. Sometimes I can access to a window, but always with less or more difficulties.
I've tried to disable my braille terminal (pappenmeier) but there is no change.
What could I do ?
Thanks in advance for your help.

Alain