I am sure that I have used the client copy profile SAP_CUSV to update the config on a training master client without the application data being deleted. A recent copy using this profile has deleted the application data though. Are you aware of any changes to the profiles? We use SAP R/3 4.5B HP48.
Actually all copy profiles with the exception of SAP_USER overwrite the target client. So, SAP_CUSV wipes out the target client's data.
This was first published in May 2002