Postgresql server "crash" after some day

Hi all,

I have some strange problems with postgres.
After some days it works in local but it doesn't listen on port 5432 for remote request.

I can make a connection from local host but I can't from remote host. If I try to make a connection from remote host the server returns me the classic remote error:

could not connect to server ... is the server running on host ... and accepting TCP/IP connections on port 5432?

This problem happens after some day that I have start the server.
There is no particular error in the log file (the server seems to work)

PostgreSql version: 8.0.3
on FreeBSD 5.3

Thanks in advance.