Just a note to say I’m still working on full support for OverDrive books in Bookmark following the iOS 5 changes for Windows users. It’s coming along but not yet ready for wider testing. I wish I could devote more time to it but unfortunately Bookmark doesn’t pay all the bills and my job is very busy right now.
Sorry for it taking so long! I feel your pain and I’ll do my best to have 1.6 ready for beta testing in a couple of weeks.