HTML Style shows in ticket

[trashbox]

How can we stop kayako from adding to the ticket an HTML mail with this content (style tag), assuming we have "Strip Tags" enabled and customer e-mail doesn't contain a plain text version:

body {
font-family: arial;
font-size: 10pt;
color: #333333;
alink: #FFFFFF;
margin-left: 20px;
margin-top: 95px;
background-position: top left;
background-repeat: no-repeat;
}