mpc sysex bug?

My mpc is hanging on sending sysex. To reproduce:

1. record a sysex patch dump from a synth (I'm using a Nord Lead 2x)
2. play it back

Everything works ok.

3. Go into step edit mode.
4. Select the sysex event.
5. Hold down edit, then press move.
6. Move the sysex message to start on a bar boundary, like the beginning of the first or second bar.
7. Go back to the main screen.
8. Hit play again.

This time, the mpc chokes on playback. From the lcd screen of the Nord it looks like it's sending the sysex message over and over again, in a loop. Can anybody else reproduce this?

Also, it looks like the sysex message is getting sent even if the track its on is muted during playback. This isn't right, is it?

I'm using the JJ os, by the way. I've reposted this question over there. Shouldn't have posted it in this forum.