I'm going to add an entry to our bug database about it and we'll investigate the issue soon. Interestingly, we don't experience this problem in our compilations though we have a Master_GDL file - puzzler. Thank you for the report.
Off-topic p.s.: I just leafed through your new book and I like it very much. I'm planning to read it thoroughly - it seems to be very useful!
ArchiCAD Development - GDL Team
AC13, AC14 and upwards...