If ROM downgrade is attempted from 2010.03.30 or later to 2010.03.01 or earlier using HP SUM for ProLiant G6 servers, the ROM components with unsupported version are automatically removed from the updates to be installed. ROM components do not have the ability to block downgrades.
This behavior is by design, and HP recommends that you do not copy the ROM components containing the unsupported versions in the HP SUM repository.