Rob van der Does
ViX Beta Tester
A HDMI matrix? Is that a HDMI switch? If so, just try it once without it (so direct connection to TV). I've also had a very strange issue with a HDMI switch (quite some time ago, not related to this, but just to show that HDMI handshakes can invoke issues, albeit seldom).
Or even a Scart connection, if you have to (and disconnect the HDMI lead from the box).
Or even a Scart connection, if you have to (and disconnect the HDMI lead from the box).
