> Weird, I was pretty sure there was a problem either on mame/chdman part or on cmpro > part when the new format came out. I clearly remember many complains about chd being > corrupted or permanently deleted.
chdman can't corrupt or permanently delete anything. Worst it can do is convert your old working v4 chds to incorrect v5 ones. And AFAIK most people had the presence of mind not to delete their old chds after conversion so no harm was possible.