That's really odd Chris.
I ran Matsui Silver last month.  Got a quart sample from Nick at Ryonet.  Printed the silver with no modification through a 180LX and a second color - I added 10% violet to Matsui silver - with flashing in between also through a 180LX.  The image was also indexed at 150 dpi.  
No issues with opacity, clearing the screen, or washability.  It looks just as good after 10 washes (well, almost as good 

).
I will try and post a pic...