Sounds like the grid is taking over the formatting of that decimal value. You can force it by putting this in the grid InitializeLayout event:
urgrid.DisplayLayout.Bands[0].Columns["UrColName"].Format = "###,##0.00";
Another option is to cast the BAQs result to a string, then you dont have to worry about it. If you ever need to edit this field then this is not a good option (if it ever was)