Openshift + Meteor = listen EACCES? - node.js

Question

I deployed Meteor.js on a Node 0.6 + Mongo 2.2 Openshift cartridge with a custom Node 0.8.24 installed in the data dir (sort of like this tutorial).
I do set the right ports before calling the app. My code in server.js looks like that:
// Setup env
process.env.ROOT_URL = "http://" + (process.env.OPENSHIFT_APP_DNS || "localhost");
process.env.MONGO_URL = (process.env.OPENSHIFT_MONGODB_DB_URL + process.env.OPENSHIFT_APP_NAME) || "mongodb://localhost:27017/";
process.env.PORT = process.env.OPENSHIFT_NODEJS_PORT || 8000;
process.env.IP = process.env.OPENSHIFT_NODEJS_IP || '0.0.0.0';
// Show connection details on startup
console.log("MONGO_URL IS: " + process.env.MONGO_URL);
console.log("ROOT_URL IS: " + process.env.ROOT_URL);
console.log("PORT: " + process.env.PORT);
console.log("IP: " + process.env.IP);
require(require('path').join(__dirname, 'main.js'));
Then, when I rhc app restart myappname the app, I get:
> node server.js
MONGO_URL IS: mongodb://<login>:<pass>#127.5.x.x:27017/<myapp>
ROOT_URL IS: http://<myappname>-<mydomain>.rhcloud.com
PORT: 8080
IP: 127.5.x.x
events.js:71
throw arguments[1]; // Unhandled 'error' event
^
Error: listen EACCES
at errnoException (net.js:770:11)
at Server._listen2 (net.js:893:19)
at listen (net.js:932:10)
at Server.listen (net.js:1006:9)
at dns.js:72:18
at process.startup.processNextTick.process._tickCallback (node.js:245:9)
npm info <mydomain>#0.0.1 Failed to exec start script
npm ERR! weird error 1
npm ERR! not ok code 0
main.js is he regular entry point for my Meteor app.
The env settings look like the right ones. Why do I keep getting this EACCESS?