SetItemDataSources returns an error when data source properties are set on a linked report item type.
An rsDataSourceNotFound error is returned if a data source that is not associated with the item is passed into the method.
When the Item type is a model, the specified value must be a single DataSourceReference. In this case, supplying an array of DataSource objects returns an error.
When the type of Item specified is a model, the DataSourceReference specified cannot reference a model or have data source credentials set to Prompt.
If multiple data sources exist on an item, only those data sources that are being changed may be submitted.