The video is an example of what happens when I import a clip, which had previously played fine, into videopad. I just used a basic screen recording I had lying around. I'll try to get a better video showing it within videopad, but audio is a no-no because the only way I can add the audio in is buy USING videopad, and then you won't be able to see it.
This is the link to the manufacurer's website page for the laptop, with the specs on, because it seemed silly to copy it all.
I've been using videopad fine on this laptop for a while, so it seemed unlikely that the graphics card or whatever had suddenly just broken. I assumed I'd pressed a button or changed a setting, but I tried a re-install and it still happens. I don't get this with any other programs.