NodeJS SSL Error

I can't seem to get SSL working for a V0.10.3 NodeJS app that uses Express 3 under Ubuntu 12.04. I'm getting the following error in Chrome:

Error 107 (net::ERR_SSL_PROTOCOL_ERROR): SSL protocol error

I have the following in my app.js file:

var privateKey = fs.readFileSync('./ssl/private.key');
var certificate = fs.readFileSync('./ssl/cert.crt');
var godaddy = fs.readFileSync('./ssl/gd_bundle.crt');

var options = {
        key: privateKey,
        cert: certificate,
        ca: godaddy
};
https.createServer(options, app).listen(3000, function(){
    console.log("Express https server listening on port 3000");
});

A similar setup using a self-signed cert works just fine on my development box. Any idea where I'm going wrong here?