Hi Jim,
Thanks for the super fast response. Yes, with HD I mean my local harddisk in the PC.
I have tried all the different filetypes I have (flac, mp3, aac) and it occurs with all of them, also when I play a CD on the optical drive of the PC. Bitrate and sampling rate (and all the other parameters I tried) are displayed correctly, but bit depth simply refuses. In the meantime I also tried a PC with XP on it, thinking it was a Win7 or Win8 thing, but the behaviour is exactly the same.
I'm puzzled.