Nodeunit not detecting done()

Trying to get up to speed with node.js and nodeunit but am finding an issue with nodeunit where it's not seeing the call to test.done() in one of the tests.

The code:

// Added for clarity.
var client = require("restify").createJsonClient({
    "version": "*",
    "url": "http://localhost:" + server.Port
});

exports["tests"] = {
    "setUp": function (callback) {
        server.StartServer();
        callback();
    },
    "tearDown": function (callback) {
        callback();
    },
    "CanIHaveSomeTeaPlease?": function (test) {
        test.expect(4);
        client.get("/tea", function (err, req, res, data) {
            test.equal(err.statusCode, 418, "Expected ImATeapot Error.");
            test.equal(err.message, "Want a biscuit?", "Expected to be asked if I want a buscuit.");
            test.equal(err.restCode, "ImATeapotError");
            test.equal(err.name, "ImATeapotError");
            test.done();
        });
    },

    // Note: I expect this test to fail as it is a copy of the above
    //       test on a different url that doesn't return the ImATeapot
    //       HTTP error. But it doesn't look like it's detecting it
    //       properly.

    "TakeThisInfo": function (test) {
        test.expect(4);
        client.put("/push", {
            "hello": "world"
        }, function (err, req, res, data) {
            test.equal(err.statusCode, 418, "Expected ImATeapot Error.");
            test.equal(err.message, "Want a biscuit?", "Expected to be asked if I want a buscuit.");
            test.equal(err.restCode, "ImATeapotError");
            test.equal(err.name, "ImATeapotError");
            test.done();
        });
    }
};

Output:

FAILURES: Undone tests (or their setups/teardowns):
- tests - TakeThisInfo

To fix this, make sure all tests call test.done()

I'm hoping it is something stupid.

Versions:-

Node: 0.10.21
NPM: 1.3.11
Nodeunit: 0.8.2
Grunt-CLI: 0.1.10
Grunt: 0.4.1

First, I don't know what "server" is in your code, but I would expect it to be asynchronous, so to have something more like this in your setUp function:

function (callback) {
  server.StartServer(function(){
    callback();
  });
}

Second, keep present that nodeunit executes the startUp and the tearDown functions after and before EVERY test so I suspect you are starting your server 2 times (as in the tearDown you are not really closing it).