What ComcastAndrew said - both the Bucs game and the Dolphins game were on Fox at 1:00, and apparently the Fox station in your area decided that there are more Dolphins fans than Bucs fans.
Correction: apparently, the decision is made by the NFL and the network - the station itself has little, if any, say in the matter.
Presumably, Fox wants the station to air the game it thinks will get the most people to watch it - and, more importantly for Fox, the commercials that go with it.
Note that this may happen next week as well, as both teams have games on Fox at 1:00. After that, though, it looks like all of the Bucs Sunday games will be on Fox, while all of the Dolphins Sunday games will be on CBS. However, there's a chance (a slim one, but it's possible) that, when it's not a Fox doubleheader day (after next week, the remaining ones are 11/11, 11/25, 12/16, and 12/23), your Fox station may decide that it's just not worth showing its one game that day against the Dolphins game on CBS, even if the Bucs are playing.