Hello,
Some background. 
I have a BT YouView box (larger last years model). I like to watch ITV4 programs but the only way I can get them is on the ITVPlayer.
I had the same problem previously with Demand 5 who suggested that it was " the change over " from adverts to program that wasn't being properly handled by my ISP providers' servers.
I pointed out at the time other replay services were working OK.
Problem. 
This week I have tried in vain to watch a program on ITVPlayer via my BTBox; the first part of the program plays OK until the adverts, then, after the adverts, it jumps back to the page with [ watch again ] on the screen.
After two days of trying I decided to try using my PC; everything worked as expected and I have finally been able to watch my program.
Question. Anyone else experienced this ?? Is it a BTBox or a YouView problem ?

Not on fibre ( yet ! )