Confusion about iPad scrobbling

Hi, I've just changed to ScrobblePod from iScrobbler. I've also just got an iPad, which is the only iOS device I have.

What I'm seeing is this: when I sync the iPad, ScrobblePod doesn't notice the new tracks. When I subsequently sync an older iPod (fairly old nano), ScrobblePod notices, and scrobbles anything on the older iPod, as well as the pending tracks from the iPad.

Is that the behaviour I should expect? I'm running Snow Leopard, and iTunes, both up to date.

Thanks