Hi Vince,
Is your black level set to Light or Dark? (you mentioned it was set to ‘low’ – is that dark?) If so, have you tried changing that to light?
Did you also use the VP403 six months ago when you calibrated it and were you able to see the BTB on the test pattern? Also wanted to ask you if you’re connecting the VP403 directly to the display when you’re putting up the patterns, or if you’re running it through an AVR.
Greg