Oh, I see. If that's the case, the problem seems to be on your end, since there would be nothing on my end that would cause the page to render good most of the time but bad every so often, and then be fixed on refresh.
DaniWeb's browser rendering cannot be compared to other forums because DaniWeb is very CSS-heavy, which most other forums aren't. For some reason your web browser sometimes has trouble rendering the CSS correctly, but on refresh, it auto-corrects itself, so there can't be anything wrong with the CSS. Does this ever happen with any other sites?
Then I point you back to how the problem is unrelated to DaniWeb's code and is most likely on your end. Something funky is going on with your installation of Opera, whether it's the browser itself, or the way your browser interacts with your system.