When PBB Resource Labels use Bold and Italic characters they don't work properly.
For details, please see thread at http://community.logos.com/forums/p/36779/275818.aspx#275818
This is a cross-platform issue - it was originally reported on Mac and I reproduced it on Windows.
Graham
I've responded in the original thread that this isn't a bug and that consistent syntax formatting is necessary. It wasn't documented, though, so I've added it to the Personal Books Tool support article FAQs, and it will be added to Help. Thanks.