Where is my database gone ?

My database coraux isn't listed anymore when i use psql -l, altough i can still
connect to it using psql coraux, but there isn't any tables listed by \dt.
Files are still present in $PGDATA, with their content.
What's the problem, and how can i recover it ?
 --  --
Guillaume Rousse
*******************************************
Iremia - Universit� de la R�union
15 avenue Ren� Cassin, BP 7151
97715 Saint Denis, messagerie cedex 9
Tel:0262938287 Fax:0262938260 ICQ:10756815
Mail:Guillaume.Rousse@univ-reunion.fr

BRIDGEKEEPER: What... is the air-speed velocity of an unladen swallow?
ARTHUR: What do you mean? An African or European swallow?