Trying To Play Html5 Tells Me To Play In Media Player Why??


Need a bit of help here with something that is to be honest driving me mad.I went on to game and clicked one of there videos, the halo reach one, and I get the now customary "click here to play on ipod"(PIC 1), now I do remember some time ago, that it did indeed used to play ok that way.but me and a friend just been discussing something and I have this problem were now for some reason when I now click on one of the ipod links, I get a white page with "click here to download, or play in media player"(PIC 2)
The funny thing is my friend clicked the same video and his played fine.It has also happened on a few other occasions on other sites to.So can someone please tell me why this has started happening, and how do I get back to playing my Html5 videos on my Ipad.