playing of bbc videos, the player is reloading making an echo as it plays the sound at the same time. what could be the problem?

when i play a video on the bbc.co.uk webside there is an echo of sound, the video will play for about 10 seconds then it buffers after which the sound is repeated causing an echo. ive tried it on a lesser quality browser (internet explorer ten) and there is no problem. all other sites seem to be fine ie youtube. == URL of affected sites == http://www.bbc.co.uk