Could this be what happened to our book?
Yes, it could. I checked and the reviews are all still there and the email I got back claimed that the book is still active, so I'll be calling the Customer Service number they gave me yesterday when they come to work tomorrow. Yeah, I think you could classify that book as "conservative".
How many reviews did you have, previously?
Incredible that they (Amazon) can get away with this.
Thankful that we have our own FR source, as proof that this is really happening.