This is what I did...
Removed the dongle. Placed next to sensor. Pressed the button on the dongle to make the light flash. Pressed tamper switch on sensor three times (dongle blinks more rapidly, then goes back to blinking like normal). Put dongle back in core. Wizard starts, click on cancel. Asked to reload router - yes. Go into webadmin, find generic sensor (child of "z-wave security interface", child of "Zwave"). Change name to "DoorTest", specified a room, and chose the door icon. Have then gone into "Active Sensors" and selected "Security" in dropdown menu for DoorTest under "armed - away".
Then, if I arm the alarm, moving the magnet away from the main part of the sensor does not give a security breach, but as I said before, the tamper switch DOES give a security breach (pretty much instantly), when the sensor is picked up from the table.
Is any more than this required from the point of view of setting up the associations? I would have thought that if the tamper switch is setting off the alarm, then it must be setup correctly?