settled on 2M and 1uF cap across the switch to slow things down , so
shorting the terminals with a piece of wire , as fast as possible, no
longer changed the mode each short contact.
All the sophistication contained in a 144 pin DSP chip, let down by the
lack of a C and an R across a switch. I won't add C+Rs to the other 2
switches, wait until if/when required, but probably the same design flaw