The problem is now fixed. It turns out that the Loopback Network Interface wasn't working properly. I came to realise that any attempt to access anything via 127.0.0.1 or localhost was hanging for an extended period. 'ifup lo' told me I had a duplicate command at line 16 of /etc/network/interfaces. The line wasn't a duplicate (it said 'manual ppp0') but I took it out and hey presto, ifup lo didn't give me an error, and everything works.
The problem is now fixed. It turns out that the Loopback Network Interface wasn't working properly. I came to realise that any attempt to access anything via 127.0.0.1 or localhost was hanging for an extended period. 'ifup lo' told me I had a duplicate command at line 16 of /etc/network/ interfaces. The line wasn't a duplicate (it said 'manual ppp0') but I took it out and hey presto, ifup lo didn't give me an error, and everything works.