i think the flash player is too slow to handle this. i've tried some workarounds
but none work too well - may be best to wait for diablo's faster flash player and
see if that is sufficient.

for the record:

1. use "wii" user-agent in browser. this gives a flash7 compatible iplayer but
in my opinion performance is much the same (may be marginally better but
difficult to tell).

2. download iphone mp4 version using iplayer-dl script. this is high quality
h264 and mplayer is not able to decode it fast enough. with mplayer options
"-lavcops gray" it is watchable (but grey!).