Issue with this.body

[markgoldin]

I think this problem has something to do with a way the SC renders the screen.
Here is a scenario.
Title:
"ListGrid placed on one of tabs in a TabSet"

this.lstPersonalInjuries = isc.ListGridComboBoxEdit.create({
dataSource: "PersonalInjuries", 
width: 440,
height:180, 
listEndEditAction:"next",
canEdit:true,
editEvent: "click",
showHeader: true,
fields:[
{name: "list_id", title: "List", type: "text", length: 50, width:220
},
{name: "numberinjured", title: "Number Injured", type: "integer", length: 2, width:95
},
{name: "numberfatal", title: "Number Fatal", type: "integer", length: 2, width:95
},
{name:"remove", showTitle: false,  type:"header", width: 20, defaultValue: "",
formatCellValue :"isc.Canvas.imgHTML('../../../common/images/scdelete.jpg', 16, 16)"
}
]
});

Data for the control:

isc.ResultSet.create
({
ID: resultSetName,
dataSource : dataSourceObject,
initialData : DSRecords
});	
ListGrid.setData(eval(resultSetName));
if (ListGrid.data.getLength() == 0)	
ListGrid.startEditingNew();
}
}

DataSource:

 isc.DataSource.create({
	ID:"PersonalInjuries",
	dataFormat:"xml",
	dataURL:"url",
	dataProtocol:"postParams",
	recordXPath:"//personalinjuries",
        fields:[
        {name:"id", primaryKey:true, hidden:true, type:"sequence"},
        {name:"file_id", primaryKey:true},
        {name:"list_id"},
        {name:"numberinjured"},
        {name:"numberfatal"}
    ]
 });

Problem only occurs for the ListGrid without data.
Description of a problem:
When I load data into the control for a first time everything is fine. But if I run again I am getting this:

08:32:36.501:XRP8:WARN:Log:Error:
	''this.body' is null or not an object'
	in http://localhost/beltrailway/mainapplication/forms/main.htm
	at line 711
    ListGrid.$33w(_1=>1195137081306, _2=>"programmatic", _3=>undef)
    ListGrid.cancelEditing(_1=>undef)
    ListGrid.discardEdits(_1=>0, _2=>undef)
    ListGrid.discardAllEdits(_1=>undef, _2=>undef)
    ListGrid.setData(_1=>[ResultSet ID:RSPersonalInjuries])
    populateComboDSUseParameters(xmlDoc=>[XMLDoc <VFPData>],  xmlText=>"<?xml version = "1.0" encoding="Windows-..."[7318],  
									   DSArray=>Array[21],  objectTypeArray=>Array[21],  objectNameArray=>Array[21],  valueFieldArray=>Array[21],  displayFieldArray=>undef,  gridFieldArray=>undef)
    $37b(xmlDoc=>[XMLDoc <VFPData>],  xmlText=>"<?xml version = "1.0" encoding="Windows-..."[7318], Obj, Obj)
    Class.fireCallback(_1=>$37b(), _2=>"xmlDoc,xmlText,rpcResponse,rpcRequest", _3=>Array[4], _4=>undef, _5=>undef) on [Class XMLTools]
    XMLTools.$37c(_1=>Obj, _2=>"<?xml version = "1.0" encoding="Windows-..."[7318], _3=>Obj)
    ** recursed on Class.fireCallback

Another detail. It will work fine as long as a tab that the ListGrid is on is selected. Another words, if I allow a focus to get onto ListGrid it works fine.
It also works if I am not doing ListGrid.startEditingNew(); after data is loaded.

Hope, it is clear and can give you a clue of what's going on.

Thanks