Sequencer sync with VST Hosts?

I have been trying to help out a friend of mine who is a Reaktor novice. He's caught that bug -- the one where it seems super-awesome to build your own sequencer.

After many iterations I have an event table based sequencer that SORT OF works. But if I pull it into Ableton Live, it is not synced with song position. All you have to do is clear a pattern and add one note on the downbeat, and turn on the metronome, and you'll hear what the problem is.

So what's the proper, reliable way to clock a sequencer? I used a counter driven by a a Sync Pulse. But it looks like my method of restarting the counter must be wonky, because the only thing certain about when the zero step in the sequence triggers is that it WON'T trigger on the downbeat!