If you browse the forum on a regular mobile browser (as opposed to Tapatalk), VU regularly sends you a message that completely messes up the layout. I'm not sure what message, because it's unreadable. It creates a huge blank page that's really annoying to get rid of, instead of displaying the site.
To fix it, go to the "Close this message" link at the bottom of the page (either scroll down to it, which takes forever, or simply look for "close" with the browser's find function), tap on the link and it'll fix it for a while.