on my website in test (www.donotopen.org/wp_site), I encounter that issue :
on all browser it looks fine, on my iPhone 4s iOS6, it looks nice, but on my iPad (1st gen iOS 5.1.1) my web font (helvetica neue light) looks weird, the font shape seems to be fine but in place of my site title ("DO NOT OPEN") I got this : "HS RSX S TI R".
I thought it was the font generated that was misunderstood by the iPad, but I put a static file in my theme folder and the font looks great. So I figured out it was the mix between wordpress, iOS and the web-font that present a bug. Anyone has info on this?