I have been using my product with no issues until this weekend, I took the unit away and plugged in to another TV using HDMI. It worked initially but after disconnecting and reconnecting, the HDMI out stopped displaying a picture. When I returned home, I plugged it back into the original configuration but the HDMI is not outputting a signal that my HDMI Matrix 4x4 box recognises anymore (it is clearly outputting something, because my Matrix switchbox switches correctly when the unit is switched on). If I plug directly into the TV - it works fine. So it seems to me that there is a HDMI handshaking issue??? Can you suggest a solution?