SEQ din sync out to 303

[blingy]

So I've level shifted J28 with the 74HCT541 and adjusted the pulsewidth to I belive 3mS. I am now able to sync my TB-303, but curiously when I hit stop the 303 often (but not always) plays one more out of tune note that I don't think is even part of it's sequence. This doesn't happen when I sync it to my TR-707. I believe Roland's sync is running at a 50% duty cycle rather than just pulses, but I don't see how that would cause this either. I just wanted to see if this issue rang any bells for anyone. I'm using an LPC17 core and powering it via MIDI.