Preheat the oven on broiler setting. In a large bowl, combine the tomatoes, sun-dried tomatoes, garlic, olive oil, vinegar, basil, salt and pepper. Allow the mixture to sit for 10 minutes. Cut the baguette into 3/4 inch slices. On a baking sheet, arrange the baguette slices in a single layer. Broil for 1 to 2 minutes, until lightly browned. Divide the tomato mixture evenly over the baguette slices. Top the slices with mozzarella cheese. Broil for five minutes, and until the cheese is melted.