Opera Presto haven't gotten any update since 2013 and it won't get anymore. It wil get older and older with more and more problems. You should try the new version.
I am sure it has to be something wrong with his install that's causing the problem. Opera 12 still works just fine, except for a really small minuscule number of websites. No need get carried away and switch to new opera if he don't want to. There are plenty threads about issues with new opera too
I always check "Accept cookies only from sites I visit" and "Delete cookies at exit".
However, I was on one website this morning and when I exited it I checked the cookie folder and there were over one hundred of them from websites I have never even heard of. So I exited Opera completely, expecting the cookies to be gone. Unfortunately, when I restarted Opera, all the cookies were still there and I had to delete them all manually. Is there another setting that I have missed?
Thanks for all your help so far.
Looks like your connection to Opera forums was lost, please wait while we try to reconnect.