I can now watch the catch ups!
I have Norton and went to Norton Security home page, clicked on web browsing,
then clicked on ad blocker,
then configure ad blocker,
then clicked advanced,
then in the left hand defaults column I clicked "add site" and put www.itv.com. and clicked add.
I was then able to click on itv.com in the default column and put in www.itv.com in the strings column clicking "permit."
Hope this might help some other poor frustrated individual like me!!!!