I've just had sky+ upgraded to sky+160. Everything was fine for a week or so. I have 4 TVs connected to sky via a RF distribution system and now 2 of these only show sky in black and white? Analogue channels are fine but sky is b&w? I've tried changing the RF channel and retuning the TVs and I've tried fine tuning the TVs but nothing seems to work. All I've done is tidy the cables at the main TV and if I watch sky on the main TV via RF rather than scart the picture is b&w for a few seconds and then goes colour. All seems very odd to me - what could be causing this?