在WinForms中使用Linq to SQL的可更新数据网格

I'm populating a datagrid using Linq--standard kind of stuff (code below). For some reason however my ultraDataGrid is stuck in some kind of read-only mode. I've checked all the grid properties I can think of. Is that a result of binding to a Linq data source? Anyone have example code of an updatable grid that uses Linq?I'm populating a datagrid using Linq--standard