CSS : Border in IE8 - html

Question

I have dialog with html :
<div id="sample">
<div class="sample-wraper">
<a class="modal_close" href="#"></a>
<form id="Form1" name="Form1" method="post">
<table id="tt">
<tr align="center">
<td colspan="2" id="naam"><b>Cha test</b></td>
</tr>
<tr>
<td colspan="2">
<div id="boodschap" class="text" style="border-right: 1px solid; border-top: 1px solid; overflow: auto;
border-left: 1px solid; width: 468px; height: 182px; border-bottom: 1px solid;
background-color: white">njnknkkm</div>
</td>
</tr>
<tr>
<td colspan="2">
<textarea id="antwoord" name="antwoord" class="text"
style="width: 465px; height: 182px; border-width: 1px; border-style: solid; border-color: black;"
onkeydown="textCounter(antwoord,aantal,1000)"
onkeyup="textCounter(antwoord,aantal,1000)"></textarea>
</td>
</tr>
<tr>
<td class="text" align="left" width="210">
Caráters permitidas
<input readonly type="text" name="aantal" size="3" maxlength="4" value="1000" id="aantal"></td>
<td align="right">
<input id="Submit" name="Submit" type="button" value="Enviar" onclick="submitForm();"
class="button" style="width: 130px">
</td>
</tr>
</table>
<input id="IdTo" name="IdTo" type="hidden">
</form>
</div>
and css like this :
#sample {
background: none repeat scroll 0 0 #FFFFFF;
border-radius: 5px;
box-shadow: 0 0 4px rgba(0, 0, 0, 0.7);
border: 1px solid;
display: none;
padding: 15px 10px 10px;
position:absolute !important;
}
.modal_close {
background: url("Close-icon-download-182005456677-png/button.png") no-repeat scroll 0 0 rgba(0, 0, 0, 0);
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='Close-icon-download-182005456677-png/button.png',sizingMethod='scale');
-ms-filter: "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='Close-icon-download-182005456677-png/button.png',sizingMethod='scale')";
display: block;
height: 20px;
position: absolute;
right: 10px;
top: 10px;
width: 20px;
z-index: 2;
}
Problem is that in IE8 on this dialog in top-left corner i get some square, which disappears if i remove border from dialog (#sample).
http://clip2net.com/s/i6klpi (sample of problem)
In IE7 and IE9 i didn't get this "feature" in corner.
I found this post about problem with IE borders http://www.brasee.com/displayPost.htm?postId=64. As my dialog is with position absolute (this is for not moving dialog when scrolls) i add wrapper of this dialog. So i set for dialog position relative and for wrapper position absolute. But this also didn't help. Get this result: clip2net.com/s/i6lcKz