Ibooks bookmark syncing cell data usage

While trying to track down why my cell data usage is soaring in IOS 6, I found that syncing iBooks bookmarks drains 125K or more each and every time I switch from that app to any other on my iPhone.

I was shocked.

125K to sync the ONE book I have open currently?

Is this true for everyone? Was it that high in IOS 5? Does it update all 600 books? Or just 200 I may have opened since downloading them? If it does, then there SHOULD be an option to sync only the currently open book, surely that isn't going to suck 124K of my cell data.