Hi Lee,
With your original system configuration and the new TV, can you check to see if the 30ms Delay for DTS noise tick box is checked in the config software? This is shown on page 92 of the 568 manual. See Duncan's Meridian Info at the top of this website for a copy of the manual.

I've had a similar issue with my system when the youview box is set to surround sound output. As the TV programs are broadcast in a mixture of 2 channel and surround, I used to get the same annoying clicks. Switching on the DTS delay gets over this.

Thanks,
Peter

Clever & Simple
Meridian Dealer In South West London
for my personal account please see PeterRW