by H.G.Muller » 03 Sep 2014, 21:40
That is not a bug, but a feature. The 'Own Book' options are not persistent, like any option that belongs to an engine (i.e. comes in a 'first' and 'second' variety). Because the next time you might run with other engines, and whether the current engine has an own book or not doesn't mean that the engine you will be using next time has a book.
Such options are intended for installing with the engine: in the Load Engine dialog you can tick whether the engine should use GUI book (and if it does, this will untick the 'Own Book' option for that engine every time you load it). In this case there is also a global option effective during tourneys, which you can set in the Tournament Dialog: "discourage own books". This unticks the 'Own Book' options when the engine is loaded for the tourney by default, so that engines will be using GUI book, unless they are explicitly installed to NOT use GUI book. (Which usually isn't the case, as not using the GUI book is the default setting, so engines that don't want to use it typically don't specify anything about book at all, but just use the default.)