Background Turns Black When Saving Bitmap - C#

I am currently trying to save a bitmap image, but the background is changing to black.

I can "Save As" the image perfectly fine. I can also "Save" the image as well. Which was much more difficult because I had to overwrite the existing image.

However, when I "save" my image the background is turning black. And I have no idea what is causing it.

Here is my code:

Bitmap tempImage = new Bitmap(DrawArea);

DrawArea.Dispose();

if (extension == ".jpeg")
    tempImage.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
else
    tempImage.Save(fileName, System.Drawing.Imaging.ImageFormat.Bmp);

DrawArea = new Bitmap(tempImage);
pictureBox1.Image = DrawArea;

tempImage.Dispose();