rainborick - 5:00 pm on Aug 6, 2013 (gmt 0)
I forget the details, but I know that some webkit-based mobile browsers don't fully support position:fixed. I just don't recall if it's just Safari or if Chrome also has the problem. I believe that the problem browsers always render position:fixed as having top:0; set. I'm sure you can find the details online, but the only work-around I know of is to work with position:absolute if possible.