Do those objects - for which you hided a meaningless number - have CO items?
Did you check this already with report RKABSHOW?
See OSS note 613707 - Archiving CO_ITEM: Standardization https://launchpad.support.sap.com/#/notes/613707/E
SAP explains the messages in this note.
some more information can be found in 200480 - Archiving CO_ITEM: Too few or nothing archived and its related notes