The first episode (the pilot) was filmed in 1997. But obviously the series didn't get picked up permanently until later, continuing in 1999. That's why there was some initial discrepancies. In addition to Silvio's character, you'll also notice Tony is the boss in the first episode, while later he is a captain. And if you look closely, you'll see that both Meadow and AJ look older in the second episode when compared to the pilot. The name of the Pork Store was also different in the first one.