Sounds like you are replacing the DataSet in your dataGridCollectionView but not clearing the previous column definitions.
I would suggest that you try the following:
dgcv.ItemProperties.Clear(); (where dgcv is the existing dataGridCollectionView that you use to wrap your DataSet)
or
dg.Columns.Clear(); (where dg is your Xceed DataGrid object)
I know that I do both, but not clear if one or both is required.