Could you please try to set

    "logging": {
        "files": {
            "level": "info",
            "directory": "logs",
            "flushInterval": 5
        },


and

    "charts": {
        "pool": {
            "hashrate": {
                "enabled": true,
                "updateInterval": 3,
                "stepInterval": 10,
                "maximumPeriod": 600
            },

and check that there is something like

2014-08-14 19:32:07 Started

in /logs/chartsDataCollector_info.log, and something like

2014-08-14 19:38:46 hashrate chart collected value 93. Total sets count 50
2014-08-14 19:38:46 hashrate data: [[1408044526,0,4],[1408044538,6.75,4],.........,[1408045021,107.5,4],[1408045033,110,4],[1408045045,103,4],[1408045057,109.25,4],[1408045069,109.25,4],[1408045081,107,4],[1408045093,104.25,4],[1408045105,93.25,4],[1408045117,92.25,4]]

in /logs/charts_info.log