Couchbase times out after few seconds?

I have about 100-200k small documents which contain base64 encoded images (quite small images). I am trying to insert all these documents to the Couchbase and I keep getting this error after first 28k documents (about 185 Mb total size)

[Error: Client-Side timeout exceeded for operation. Inspect network conditions or increase the timeout] code: 23

Here is screenshot of Couchbase settings (I see only one strange thing here — free space is totally wrong, actually it is about 300GB of free space on my disk)

My code is pretty simple and looks like this

 _.forOwn(data, function (data) {
    var item_id = "item::" + uid().toString();

    db.set(item_id, data, function(err, result) {
        if (err) {
            console.log('cb error', err);
        }
        else {
            console.log('cb success', result);
        }
    });
 });

I tried to alter documents and make them smaller or larger — it doesn’t matter, after 28k database stops responding. It saves 28k in few seconds and then throws timeout. What should I do to fix this issue?

__

upd

I installed Couchbase 2.5 Enterprise and now free space is shown correctly. However I am still not able to pass through 28k limit. I am running Mac OS X 10.9.2. Maybe I should try to use Python or Java SDK for example?

This is my local machine, I just run Couchbase from Applications folder, and create client from nodejs via

var db = new couchbase.Connection({host: ‘localhost:8091’, bucket: ‘default’});

I have libcouchbase-2.3.1 installed.

Couchbase only make a windows and mac version to “play around” with couchbase. Could you spin up a few AWS VMs One Couchbase cluster w/ 3nodes and a few application machines and re-do the tests.