I just updated to 4.6.9 and found a possible glitch. I lost perhaps between 10% and 20% of the star and color ratings on my images. These are all TIF files that I have noticed so far and from what I can tell it's very random. This is from a sampling of about 40,000 photos.
I'm running Windows 7 Pro 64 bit.
UPDATE
When I open the files in Photoshop CS5 they still retain their assigned star rating.
Thanks,
Kevin