hey
the 74HC154 has inverting outputs.. so you have to send 1111 to turn all the outputs off. Have you tried that?
D
i went out and got an inverter: 74HC05
i just got 2 of the de-multiplexers to speak to one motor--going both forward and backward. i'm about to hook up a 2nd.
i think i'll not be able to address two motors at once... ah well...