Column width not working

Hi I have read the other posts in the forum. Did not find solution.

<--!  Datatables spezific files:-->
    <link href="~/datatables/dataTables.bootstrap.min.css" rel="stylesheet" />
    <script src="~/datatables/jquery.dataTables.min.js"></script>
    <script src="~/datatables/dataTables.bootstrap.min.js"></script>*

<div id="datatablestest" style="width: 460px;margin: 0 auto;">
    <table id="datatableresult" class="table table-condensed table-striped table-bordered  table-hover" cellspacing="0">       
    </table>
</div>

var daTable = $('#datatableresult').DataTable({
    "ajax": {
        "url": daUrl,
        "dataSrc": ''
    },
    "autoWidth" : false,
    "columns": [
        { data: "JourID", title: "JourID", width: '50px'},
        { data: "JourTime", title: "JourTime", width: '50px'},
        { data: "Zust1", title: "Zust1", width: '30px'},
        { data: "Dokname", title: "Dokname", width: '100px'},
        { data: "Doktype", title: "Doktype", width: '100px'},
        { data: "JourInhaltTextOnly", title: "JourInhaltTextOnly", width:'550px'},

    ],
    "paging": false,
    "scrollY": 400,
    "scrollX": true,
});

Has no effect at all.
DataTables makes column width that have nothing to do with the set options.
Am I misunderstanding completely, how this works ?
Thanks for Info
Cheers, Michael