Well, I´ve kept trying, and finally it´s responded to OK on hard reset, despite not responding to DB or DM.  Very odd - I thought they were the lowest-level resets of all.  But even then it didn behave a bit like the instructions said - no command prompt, just did its own thing, but seems to be working.  Moral is - keep trying!!  But if I want to change back to Cacko, I´ll have to get into command-line mode.  How do I do that if it doesn´t respond to DB hard reset?