grunt async task timeout

I've an async task but it timeouts in 5 seconds and grunt moves on to the next task:

grunt.registerTask("something", '', function(target){

    var done = this.async();

    function checkStatus ()
    {
        console.log('test');
        if(someCondition)
            done();
    }
    setInterval(checkStatus, 500);
});

I see 9 'test' messages in the terminal and then it just moves to the next task, without further waiting to the 'done'. I haven't found any limits or time restrictions in the code of grunt.
Why does that happen ?

grunt 0.4.8rc1