I've had a few email conversations with SteveG about this but I thought it would be worth sharing my experiences with the forum.
The syncing of ratings to the iPod still seems broken, although it's not always consistent.
Two days ago I did a complete fresh wipe and load of my iPod. I then took it out, and have listened to it over the last few days, rating a few songs in the process (changing ratings from "no rating" to a value).
I have just synced it with the "sync data to MC" box checked, and MC overwrote all the ratings that I've just applied on my iPod with the "no rating" from MC. This has happened repeatedly recently when trying to sync. Midway through the MC10 development process, though, it was working fine.
In between loading my iPod and syncing it for the first time, I haven't used MC at all. Nor have I changed the time on my PC or the time on my iPod. The time and date are set correctly on both.
I can't think why this is consistently going wrong for me. Is no-one else having problems? Or does no-one else use ratings? Is there anything I can do to try and narrow this down?