Panasonic CT-32XF55 & DSS

Is anyone out there using this TV with DSS? I just got one, and DVDs look great, but my DSS signal is a little funky. I don't know if it's because of the internal doubler or what, but the picture doesn't look very sharp and has some digital artifacting that my old set didn't show. I'm currently using S-Video connectors for both DSS & DVD.

Anyone else have this problem?