There’s a possibility that some people have their displays in the wrong resolution. Most likely reason people do this is due to font illegibility and using the wrong method to increase font size. If someone with a widescreen monitor runs a screen resolution intended for standard screen monitor, you can expect stretching, for example.
Hmmm, this seems to be a problem with your browser. I recommend to use Google Chrome as your Default browser, or use Firefox. I don’t recommend using Internet Explorer, Internet Explorer is a very bad browser these days.