From attachment.html

First bug: potentially infinite loop in JavaScript

while (!document.rmstream_{_file.ATTACH_ID}.GetClipWidth())

{

}

That code will put JavaScript into loop until GetClipWidth() returns positive result, which might be infinite if Real Media player that is not known for stability fails to load document.

Possibility of that occurring are none because of bug #2

Second bug: movie cannot be loaded if prefetch is disabled. Because of that faulty JavaScript will never be executed and controls will not be shown. As a result, both controls and JavaScript can be removed as well as whole idea of embedding RealPlayer media in posts.

On a side note, RealPlayer does not work on Mac, it does not work in most browsers on Windows.