Simon,
You say 'it keeps losing its memory' so I take it you can get it to work and set all the preprogram buttons.
It sounds as if you have the 'continuous live' (yellow) and the 'switched live' (red) swapped over. This means every time you switch it off it loses all power and forgets its settings. Change those wires over and it should work ok.
Mel, August 2007