It's not script. It's just basic html that'll embed a flash object into a html page and https://i.imgur.com/0Djlk6A.png is the end result.
Yeah, I haven't got an answer for that. I think it's probably just the client in question or the browser. I got the same problem on chrome.
Yeah, I got lazy. Could have used CSS but didn't feel like it at the time. Probably could have centered it on the page correctly.