When I've tried to look at preview pages, I get this message:
Server Error
404 - File or directory not found.
The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.
I noticed this again today with a new pre-pub:
http://www.logos.com/product/9919/handbook-on-the-old-testament-series
I'll notify customer service via email, too.