root@host:/export/newtos/etc# pear install MDB
Connection to `pear.php.net:80' failed: Connection refused
I realised that the machine was behind a squid web proxy which wasn't allowing the connection through.. it took a bit of fiddling around and googling, but it seems the easy way around this is to define an enviromment variable called $http_proxy like so:
root@host:/export/newtos/etc# export http_proxy=http://192.168.1.2:3000
Just make sure you have the right IP and port number in place..