I'm not sure it this counts as a bug, but it's certainly a feature:
The following action causes the PC to make a clunking sound. From the main menu select File > Open Project to get the Open Project dialog. Open the "Look in:" drop down menu so that the "My Computer" and the various drives are displayed. Move the mouse pointer vertically over the various drives (without clicking) so that each drive is highlighted.
As the floppy drive gains or loses the highlight it goes 'clunk'.
I think it has also happened on other occasions but I can't reproduce it.
I can post it as a bug, if desired but it's (probably) not really a big deal.