VBulletin and the mobile version of Safari have had a number of compatibility issues and bugs reported. I won't go into the causes (tech nerd stuff) but I do have an easy fix: install Google Chrome on your iPad and browse the forum with that. I like a full browser version of the forum on a tablet, and I only use the mobile app on my phone. Have had zero issues using Chrome.
"You can't buy happiness, but you can buy an RV. And that is pretty close."