Thanks for the response.
I have uninstalled Adblock Plus for Android from my tablet, and instead I'm using Firefox with Adobe Flash Player and Adblock Plus for Firefox.
This works fine, except for one issue - when watching video streams, the screen blanking still operates. I got around that one by installing the App "Screen Timeout Toggle". I would have preferred to use Chrome browser as it is integrated with Android sufficiently to avoid the blanking issue, but I am very happy to use Firefox as I'm quite familiar with it and find it more flexible than Chrome.
It's a bit of work setting everything up, especially as Google have removed Adobe Flash Player from the Play Store, but there are ways around that.
Adblock Plus for Firefox does its thing and blocks annoying ads from webpages and even video ads from catchup TV!
BTW - Although I have ticked "Notify me when a reply is posted", I am not receiving any notifications. I have tried to check / change the email address stored in the system, but I can't find how to do that.