ESP8266: CIPSTART failed?

Manually checking version of my ESP8266's indicates they're the right version.

(serial monitor @9600 baud):
AT+GMR

0018000902-AI03

OK

So I should be good right?

Serial4.setup(9600, { rx: C11, tx : C10 });
var wifi = require("ESP8266WiFi").connect(Serial4, function(err) {
  if (err) throw err;
  wifi.reset(function(err) {
    if (err) throw err;
    console.log("Connecting to WiFi");
    wifi.connect("(snip)","(snip)", function(err) {
      if (err) throw err;
      console.log("Connected");
      // Now you can do something, like an HTTP request
      require("http").get("http://www.pur3.co.uk/hello.txt", function(res) {
        console.log("Response: ",res);
        res.on('data', function(d) {
          console.log("--->"+d);
        });
      });
    });
  });
});

>echo(0);
=undefined
Connecting to WiFi
Connected
ERROR: Socket error -1 while sending
Uncaught Error: CIPSTART failed
 at line 1 col 207
...d 0,Error("CIPSTART failed");}
                               ^
in function "d" called from line 1 col 26
{e=void 0;var b;d&&(b=d(a))?(e=g,d=b):clearTimeout(c);void 0...
                          ^
in function "e" called from line 1 col 291
...f&&(g[f](d),n=!0);n||e&&e(d)}b=b.substr(a+1);"\n"==b[0]&&(b=...
                               ^
in function called from system
>Uncaught Error: CIPSTART failed
 at line 1 col 207
...d 0,Error("CIPSTART failed");}
                               ^
in function "d" called from line 1 col 16
{e=void 0;d&&d()}
                ^
in function called from system
{if(a)throw a;wifi.reset(function(a){if(a)throw a;console.lo...
             ^
in function "a" called from line 1 col 100
...a("No 'ready' after AT+RST");else return c}
                               ^
in function "d" called from line 1 col 16
{e=void 0;d&&d()}
                ^
in function called from system
wifi.getVersion(print)
=undefined
null undefined
>wifi.getVersion(print)
=undefined
null undefined

Any thoughts on where to go from here, or what that error means?