are you able to connect via Cable in?
And by Fuzzy do you mean there is some static on the screen or just that the over-all picture quality is less?
What TV size did you have before? Tube/Flat/LCD etc
I would be willing to bet that you are just experiencing why so many switch to HD Receivers with LCD's and Plasma TV's , Believe it or not.. SD actually looks better on a Tube style TV than it does on a LCD. I upgraded the TV in my Bedroom with a 42" LCD with a SD receiver and it totally looks worse than the 27" tube TV I had in there before. Eventually I will get to adding another H21 to it.
Some things to check.. are you in Super Zoom, Auto Adjust, Zoom or Stretch mode on the TV's picture format? try it on Original Format with Wide and with 4:3 selected in the receiver. you may also just be over digitizing the image.