Do Sky deliberately broadcast "normal sports programs", 401, 402,
403,
itv and bbc in lower quality to encourage people to buy their HD
package.
Compare ITV channel 3 on sky to channel 3 on freeview and the quality
seems much better on freeview than the same broadcast on sky.
I have HD and since getting it, the picture seems to have got much
blurrier than it is on our sky + box