Marc wrote:
Last night I took the rear wheel on the Dahon off, stripped it down and
repacked the bearing,adjusted the derailluer , found all the gears again
and adjusted the drum brake. While I was at it I took the front blocks
out trimmed them , reversed them and adjusted them until there were
perfect, just kissing the rim in one spot. Left the bike in the
workstand and came in. This afternoon (still in the workstand) the front
brake is as locked on as a bulldog with tetanus! How?

Has the cable outer popped out of the barrel adjuster, (or out of one of
the other bits it slots into)? effectively making the out longer, and
the inner relatively shorter. If it has then you need to check that the
inner slides through the outer easily.