Querying Athena from Lambda function - QUEUED state?

Hi there,
I've been successfully querying s3 via athena from inside a lambda function for quite some time but it has suddenly stopped working. Further investigation shows that the response from get_query_execution() is returned a state of 'QUEUED' (which i was led to believe is not used?!)

My code snippet is as follows:
while (max_execution > 0 and state in ['RUNNING']):
max_execution = max_execution - 1
print("maxexecution=" + str(max_execution))
response = client.get_query_execution(QueryExecutionId = execution_id)

    if 'QueryExecution' in response and \  
            'Status' in response\['QueryExecution'] and \  
            'State' in response\['QueryExecution']\['Status']:  

            state = response\['QueryExecution']\['Status']\['State']  
            print(state)  
            if state == 'SUCCEEDED':  
                print("Query SUCCEEDED: {}".format(execution_id))  

                s3_key = 'athena_output/' _ execution_id _ '.csv'  
                print(s3_key)  
                local_filename = '/tmp/' _ execution_id _ '.csv'  
                print(local_filename)  

                rows = \[]  
                try:  
                    print("s3key =" + s3_key)  
                    print("localfilename = " + local_filename)  
                    s3.Bucket(BUCKET).download_file(s3_key, local_filename)  
                    with open(local_filename) as csvfile:  
                        reader = csv.DictReader(csvfile)  
                        for row in reader:  
                            rows.append(row)  
                except botocore.exceptions.ClientError as e:  
                    if e.response\['Error']\['Code'] == "404":  
                        print("The object does not exist.")  
                        print(e)  
                    else:  
                        raise  
                return json.dumps(rows)  
            elif state == 'FAILED':  
                return False  
    time.sleep(10)  
return False  

Obviously it is returning false as i don't cater for get_query_execution() returning a state of 'QUEUED' - what can cause it to return this state? From the doco i've seen this state isn't supposed to be in use yet? How should this be handled? is it as simple as adding 'QUEUED' to the while condition? e.g. while (max_execution > 0 and state in ['RUNNING', 'QUEUED'])