HELP:
I just hooked up a Samsung HL-R5067W DLP and a Samsung HT-P38 HT system to Comcast Dual Tuner Motorola cable box.

Component cable from cable box to the component video in on the TV, and the audio to the HT system.

Optical audio from Out on TV to the IN on the HT system.

When I first got the TV it was hooked up to my regular Digital cable box and all the channels showed nice and clear.
Yesterday I finally got the HD cable box and the HD channels show great, but the regular channels are now very poor, lots of pixelization, text is hard to read, watching sports is very poor because I cant make out the players as they all look fuzzy running around.

Any suggestions how why this happened when i went from the regular digital box to the HD box?
Can it be fixed?