"all I get is a box with a green 'n' black stripy horizontal bar... forever moving, but no images, no movie clip..."

That "stripy bar" is the indicator that the clip is downloading. Takes a while..

What speed is your modem running at? I'm on broadband and I have to wait a minute or so before the clip starts to play. If you're on dial-up then you'll have a long wait (probably not worth it..) Although the early Attenborough stuff is interesting, just for nostalgia value:-)

Cheers,
Diolma