Rollover Image has an unwanted grey bar under a .png image

Rollover Image has an unwanted grey bar under a .png image

I created a rollover image in Photoshop. It was created in a square shape
canvas .png. The image is a circle. I created one image normal and one
image highlighted as the rollover. The rollover image has an unwanted grey
line under it, I don't understand why it is there...
[EDIT : moved an OP comment to be a question complement]
– user2773016 1 hour ago
<a href="Specification.html" onmouseout="MM_swapImgRestore()"
onmouseover="MM_swapImage('news','','images/ipadjpiGRAYSCALE3.png',1)">
<img src="images/ipadjpiGRAYSCALE.png" width="350" height="300"
id="news" />
</missing closing a tag>