use chrome and you will be good.
I use Chrome on my iPad and it still happens. Not just SGN, it's the bb software not this specific web site.
Ummm... you're problem is that it's an Apple.
"If somebody thinks that they can pick up the phone and dial 911, and the police are going to be there to save them; that's not the case. The police are going to be there to clean up the mess." - Police Chief Mark Kessler
I don't usually use my iPad for SGN, but I do use my iPhone. Have you rebooted it recently? If you hold the round button and the power button for a few seconds you'll see the Apple symbol. This is a full reboot, more than just powering it off. I have to do it on my phone every couple of weeks when it starts acting funky.
It's not just an iPad/Apple issue. It's the way the iPad interfaces with vBulliten (software of this site). Hiding then re-showing the keyboard usually fixes it, so does closing safari and opening it back up (background it, not fully close it)