My version of Zen Writer refuses to close. It will ask me if I'm sure I want to close, and then freeze up, and the only way I can close it is by restarting my computer. If someone could offer a solution or tell me if this is actually a bug, I'd be grateful.
It seems that this is really bug. Try to uncheck "Enable auto backup" from settings dialog
Ah, that worked! Thank you very much for your help.