For these metadata types, you can't simply retrieve all of them with the
* notation. To retrieve them, you need to request them specifically by name and include the folder that they are in.
When the eclipse plugin generates the package.xml file, it is doing that work for you behind the scenes.
A good reference to consult when working with metadata is the Metadata API Developers' Guide
describeMetadata(), you will notice that certain metadataObjects are being returned with the value of
inFolder set to true. These objects have another object that is not returned from the
describeMetadata() call that are named with the word "Folder" at the end (DashboardFolder, ReportFolder, etc.). To get the metadata for these types, you should use the +Folder object names in the