jQuery Grid Plugin - jqGrid

The delfunc overridden as follows

delfunc: function (rowid)
{
    $("#grid1″).jqGrid('delGridRow', rowid,
    {
        serializeDelData: function (postdata)
        {
            postdata.a = "grid1_event";
            postdata.id = $("#grid1″).jqGrid("getRowData", rowid)["col1"].toString();
            var l = { b: postdata };
            postdata = JSON.stringify(l);
            return postdata;
        }
   })
}

This works ok, the modal form is shown and clicking the delete button successfully deletes the record.
But the problem comes when I try to delete another record.
The model form shows but clicking the delete button causes a error at  
"$("#grid1″).jqGrid("getRowData", rowid)["col1"].toString();". It seems that, after debugging in VS,

the rowid value is my old rowid value (from the previous delete), hence the rowid value does not reflect the new rowid.

I don't have this problem in my "editfunc" because "recreateForm" is true. But there is no such option here.
Is this a bug or am I using "delfunc" the wrong way?

I'm using jqgrid 4.1 and jquery 1.6.1.

Same post here: /blog/?page_id=393/help/delfunc-overriding/