So your key pressing caused this problem and then you conveniently assume FF was the cause of this? I did a search on google and found information on black borders but that isn't something from FF nor caused by FF.

I didn't assume FF was the cause of it, it was my fault - like I said

Just asking for some help resolving it, & have to put up with unhelpful trolls like yourself!

If I understand correctly, you're saying that the issue only happens with specific sites. If you managed to affect some - not all - websites with one action, I suspect you changed something in the Flash plugin.

If you can use the web without Flash, the best solution is not to use Flash. Try disabling it, and see if you still need it. For instructions, see Disable or remove Add-ons.

If you still need it, try changing some of the Flash settings (in Flash). For information, see https://www.macromedia.com/support/documentation/en/flashplayer/help/help01.html

Hi Bud,

Thanks for your reply

I've tried all those settings but no luck :(

When it first happened a few weeks ago, I googled it & found it after a few pages of searching.

It was something simple like press either Ctrl or Alt & a Letter/number, or something like that. I remember thinking at the time how rediculously easy it was... so much so that its now happened again & I've completely forgotten how to do it... & worse still I can't find the page on Google with the solution :(

It plays MP4 videos ok, no borders... but other videos end up like looking through a letterbox

Okay, let's figure what is being used to play the video. When the video plays, right-click anywhere in the video. Would you mind sending us a screenshot of the menu that appears? For instructions, see How do I create a screenshot of my problem?.