One thing that is very annoying is when I am reading a thread on the iPhone, the page would jump up or down at least half a page. So when this happens I would scroll up to see the content but there are often points in every thread where the page jumps on me so I could never really read the content. It jumps in the direction of my scrolling by about half a page when I try.
I get it on iPhone also normally when i’m reading a long post then have to try and find my place. I thought it was something to do with the ads on the site, as it always seams to stop on one.