Strange values with bar stack Open Flash Chart

Question

I'm trying to use the bar stack graph with Open Flash Chart. The JSON object I generate is containing correct values and when the chart is loaded the first part of the bar stack is correct but the ones after have gotten way of values. The JSON object:

{
"title": {
    "text": "Aktiviteter",
    "style": "{font-size: 15px; text-align: center;}"
},
"elements": [
    {
        "type": "bar_stack",
        "colours": [
            "#b727e3",
            "#f55225",
            "#16196e",
            "#b3ac3",
            "#f01673"
        ],
        "keys": [
            {
                "colour": "#b727e3",
                "text": "Utst\u00e4llningar",
                "font-size": 13
            },
            {
                "colour": "#f55225",
                "text": "Kurser",
                "font-size": 13
            },
            {
                "colour": "#16196e",
                "text": "Resor",
                "font-size": 13
            },
            {
                "colour": "#b3ac3",
                "text": "Kulturarrangemang",
                "font-size": 13
            },
            {
                "colour": "#f01673",
                "text": "F\u00f6rel\u00e4sningar",
                "font-size": 13
            }
        ],
        "values": [
            [
                {
                    "val": "205",
                    "tip": "Utst\u00e4llningar 2013<br>Antal #val#"
                },
                {
                    "val": "52",
                    "tip": "Kurser 2013<br>Antal #val#"
                },
                {
                    "val": "161",
                    "tip": "Resor 2013<br>Antal #val#"
                },
                {
                    "val": "123",
                    "tip": "Kulturarrangemang 2013<br>Antal #val#"
                },
                {
                    "val": "123",
                    "tip": "F\u00f6rel\u00e4sningar 2013<br>Antal #val#"
                }
            ]
        ],
        "on-show": {
            "type": "pop",
            "cascade": 1,
            "delay": 0.5
        }
    }
],
"x_axis": {
    "labels": {
        "rotate": 20,
        "labels": [
            "2013"
        ]
    }
},
"y_axis": {
    "min": 0,
    "steps": 66,
    "max": 830
},
"tooltip": {
    "mouse": 2
},
"bg_colour": "#FFFFFF"

}

Item #2:

{
  "val": "52",
  "tip": "Kurser 2013<br>Antal #val#"
},

, when displayed, got a value of 20 347 instead of 52 and therefore doesnt fit into the y-axis. (image http://s8.postimg.org/jfeh9u2d1/Namnlo_st.png)

I load the Chart by

<script type="text/javascript" src="js/js/swfobject.js"></script>
<script type="text/javascript">
  swfobject.embedSWF(
   "open-flash-chart.swf", "my_chart", "550", "200",
   "9.0.0", "expressInstall.swf",
    {"data-file":"get_stats2.php?action=activities%26type=total%26limit=1"}
 );

Any suggestions?