[Plugin: Contact Form 7] Issue With Custom Submit Button

Hello.

If you’ll look at my site here you’ll see a contact form 7 form. I have a custom submit button set up, and the image shows up fine except for the fact that there is a strange grey background to the image. The image is completely transparent. I’ve even tested it by making a blank transparent image in place of the submit button image and the grey box is still there. I’ve tried modifying my CSS but nothing is working. Any ideas?

Contact Form 7 Code For Button:
[submit class:contact1 “Send Form”]

CSS Below:

.contact1 {
	width: 183px;
	margin-right: 0px;
	margin-left: 5px;
	margin-top: 5px;
	margin-bottom: 10px;
	font-family: Arial, Helvetica, sans-serif;
	font-size: 13px;
	font-weight: bold;
	color: #000000;
	padding-top: 15px;
	padding-bottom: 8px;
        padding-right:0px;
	text-decoration: none;
        text-align:center;
	background-color: none;
	background-image: url(images/bookit.png);
        text-shadow:0 1px 0 #fff;
	height: 48px;
	display: block;
}

https://www.ads-software.com/extend/plugins/contact-form-7/