The company running the contest is Shelf Unbound out of Texas. I'm usually leery of any businesses coming out of Texas. It's a knee-jerk reaction to Enron and the Robber Barons.
I was pointed to the above site when I googled Shelf Unbound Lawsuits, not Bowker. So one of the things I would be curious about is if in the contract, the writer gives up her or his ownership rights.
If I were entering, I would read the contract and do a search for red flags. I hope any other writers that enter contests also read the contract before signing and sending. There was a very enticing contest I considered that was run by MeeGenius. I thought I'd send in my chapter book. Problem is, their contract spelled out that they had all future world-wide, electronic rights; your characters became theirs; and they could have other writers write in your universe without your permission.
Basically, I always read the contract and make sure what the consequences are before I send.