I have just purchased a Sony KV32LS60 and I find that the picture on Sky channels is quite grainy and the picture not very sharp. I am comparing this to my 7 year old Sony Triniton which was a much better picture. I used all the original cables from the old set. Does a decent scart lead make a real difference with the picture? There is also quite a loud hum from the top of the set. Is this normal? Thanks.