Sidebar shows scrollbars

Hello, I created my own WordPress theme for my site, my own style my coding.

I just tested my site on Internet Explorer, I just noticed that the sidebar/widgets are showing scroll bars, I tried adding some coding on the CSS but couldn’t fix the issue.

Here’s my CSS for the widgets:

#sidebar .widget {
	width:300px;
	float:right;
	background-color:rgb(0, 0, 0);
	background-color:rgba(0, 0, 0, 0.4);
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000);
	-ms-filter:"progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000)";
	font-size:13px;
	overflow:auto;
	padding-bottom:0;
	color:#FFF;
}

#sidebar .widget .widget-title {
	background-color:#FFF;
	border-bottom:thin dotted #FFF;
	color:#676767;
	font-size:14px;
	font-weight:bold;
	text-transform:uppercase;
	padding:5px;
	margin:auto;
}

Here’s my site http://www.sumbale.com

Please check it out and help me out, remember is on Internet Explorer, i’m currently on the latest Internet Explorer, thanks. I will appreciate your help.