Are you saying that you'd rather it have a transparent background, or be in a vector format? Otherwise, what exactly are you expecting?
Yes to the transparent background. According to the tutorial on signing PDF's Acrobat is suppose to do that automatically. And it does with one of my other signatures, which I created during an older version of Acrobat. But scanned in a new one and now this feature of Acrobat doesn't seem to be working as it should.