Upgrading from XHR-Polling to Websockets in Socket.io 1.0.X results in packets dropping

I have been working with a problem in Socket.io 1.0.6, where a client randomly does not receive a packet on a given protocol, and randomly does.

I have been running my node application with prefix DEBUG=* and in the browser set the variable localStorage.debug='*'. It goes as follows: 1. Client emits on 'event'. 2. Server receives on 'event' and emits on 'event'. 3. Client does receive on 'event'/client does not receive on 'event' (randomly). Debug messages approves this. I do not get any error messages, just don't receive packets.

My server now runs with this configuration, which works every time:

var io = require('socket.io')(port, { allowUpgrades : false });

Have anyone else experienced problems with upgrading transport protocols in engine.io?