could not connect to server

Dear Users,
I have this problem:
I'm running postgres 7.3 on a linux system...
I have started postmaster with -i option, but when I try to connect to
the server from another computer I obtain:

psql: could not connect to server: Nessuna rotta verso l'host
Is the server running on host "IP....." and accepting
TCP/IP connections on port 5432?

when I try to connect from the same computer running the postgres server
(using TCP/IP )
psql cave_prova -h IP.... -p 5432 -U aurora

the server answer correctly... and I can connect...
so I think the TCP/IP socket is working well!!!

can you suggest me some ideas for solving this problem???
thank you
Ivan

--
Ivan Marchesini
Department of Civil and Environmental Engineering
University of Perugia
Via G. Duranti 93/a
06125
Perugia (Italy)
e-mail: marchesini(at)unipg(dot)it
ivan(dot)marchesini(at)gmail(dot)com
tel: +39(0)755853760
fax: +39(0)755853756
jabber: geoivan73(at)jabber(dot)org