Therefore SAP says clearly:
quote
You should never use standard roles directly, but always in the form of a copy in the customer namespace. This applies particularly if you change the role.
Otherwise, you may lose data as soon as SAP delivers a change via Support Package.
unquote
Copied from SAP note #1154550, section 'Important remarks'
or
quote
You should first copy the single roles contained in the composite role to your customer namespace, adjust the open fields in line with your circumstances (for example, included child systems), and generate the corresponding profiles.
unquote
Copied from SAP note #2000585....
b.rgds, Bernhard