Live radio

[YellowYeti]

I have a script which issues the following for listening to 'live' radio 
channels:

get_iplayer --stream --flush --type=liveradio "$1" --player="mplayer 
-cache 64 -"

where $1 is the station I want to listen to.

If $1=Radio 1, Radio 2 etc. then this seems to work at least some of the 
time ( maybe 1 in every 2 or 3 attempts )
if $1= World Service then it never seems to work.

In each case, get_iplayer appears to locate the correct stream, but the 
error message I get seems to indicate problems with the cache, hence the 
--flush option ( which I'm not convinced makes any difference )

Is there anything obviously stupid about what I'm doing? Any mode 
options that need to be set up?

I have a recollection that different channels were streamed at different 
bit-rates - could this be an issue? Do I need to change parameters 
dependent on the particular channel I want to listen to?