I’m with @japes. Any ads with sidebars are interfering with the browser scrollbar/page-down key. A page refresh always loads a new ad. So if the new ad has no sidebars, you’re good. If the previous ad is reloaded or it’s another with sidebars, you’re stuffed.
I keep on refreshing until I get an ad with no sidebars. Or if a sidebar ad has block-booked DIS for a day, I use the thread scrollbar to go the latest reply and then use the browser scrollbar or page-up key to go back to the top. So making the entire thread is visible.
When the browser window is maximised, some ads continue on the left and right side of the page. Like the letter ‘n’. While other ads only appear on the top.
Just one thought: it might be worth upping that user to a ‘Member’ level 2 status. I know that as Admin I never see the adverts on the site but I have seen them when logged out. I presumed all lower levels would see the adverts or the same adverts but almost all our members are Level 2 so it’s possible the ‘bad’ adverts are only showing at that level maybe?