Chess Diagram Copyright Question

I am working on a chess tactics e-book.  I was planning on using diagrams generated by Fritz from ChessBase.  It occurred to me that there might be a copyright issue even if I credit the Fritz UI as having been used to generate the diagrams.

Does anyone know whether copyright is an issue here?

Thanks.

Hi Dave,

I'm not sure but yes, technically you might not be able to use that piece font.

I certainly would like to think that ChessBase wouldn't throw up a stink about it, but I guess you never know.  I suppose you should write to them and ask them.

However, how do all of the other authors of chess books, or all of the different chess magazines, and chess websites, get away with publishing their chess diagrams?  Are they all using public domain fonts?

There are plenty of public domain fonts out there that are very attractive and all you have to do is install them within windows to use them in Fritz.  Do a search for "fritz fonts" in the chess.com downloads area to get a pretty decent package of them.  

Chess positions/games are not copyrightable afaik.  Annotations that might come with them are, though.