jQuery Grid Plugin - jqGrid

Hi,

I'm using CouchDB with JQGrid. My Couch data looks like this:-

{"total_rows":1662,"offset":0,"rows":
    [
    {"id":"338b79f07dfe8b3877b3aa41a5205e75","key":"2004-03-05T03:59:00+00:00","value": {"date":"2004-03-05T03:59:00+00:00","signature":"sig1","name":"name1"}},
    {"id":"338b79f07dfe8b3877b3aa41a540cf58","key":"2004-03-05T03:59:00+00:00","value": {"date":"2004-03-05T03:59:00+00:00","signature":"sig2","name":"name2"}},
    {"id":"338b79f07dfe8b3877b3aa41a566ca42","key":"2004-03-05T03:59:00+00:00","value": {"date":"2004-03-05T03:59:00+00:00","signature":"sig3","name":"name3"}},
    {"id":"15add79dd3efec4f34786d5f6a33ec5c","key":"2004-07-26T14:03:00+00:00","value": {"date":"2004-07-26T14:03:00+00:00","signature":"sig4","name":"name4"}}
    ] }

My JQGrid definition looks like this:

datatype: "local",
            height: 100,
            colNames:['key', 'signature', 'name'],
            colModel:[
                {name:'key',index:'key', width:80}
                {name:'value.signature',label:'Signature', width:100, align:"right"},
                {name:'value.name',index:'name', width:80}

            ]
caption: "Load Once Example"


However, the columns for the value.signature and value.name fields are always blank. Is there anything I'm missing here as I would have expected the JSON dot notation to work?
Any pointer would be much appreciated!