I have restarted the DCS Disk2Disk processes writing to archive at LHO with,

 set CHECK_SOURCE_MD5SUM 1

in the Disk2Disk .conf files, so that the CDS .md5 files are now compared with the md5sum found by Disk2Disk before the file gets copied to the LDAS archive. (The file must also pass FrCheck to be copied, as before.)