IE9 width:auto corrupted when click on link

IE9 width:auto corrupted when click on link

I am testing an application on IE 9. The application works well on all
browsers, thoroughly tested. I have a menu which is positioned absolute
with width:auto. The menu looks fine but when I click on a link in my
menu, for those few seconds until the next page loads the menu expands
almost to the width of the whole screen. When I change the width to be
fixed (50%) the menu is OK. But this is not desirable. Here is the CSS
defining my menu, maybe there is another element affecting it?
.MegaWrapper {
position:absolute;
left:auto;
top:auto;
text-align:left;
margin-left:-45px;
*margin-left:-53px; /*hack for IE7*/
margin-top:10px; z-index:12;
width:auto;
height:auto;
border:1px solid #bdbcbd; -moz-border-radius-bottomright:9px;
-moz-border-radius-bottomleft:9px; -webkit-border-radius-bottomright:9px;
-webkit-border-radius-bottomleft:9px;
border-bottom-right-radius:9px;
border-bottom-left-radius:9px;
display:table;
font-size:85%;
background: #fbfbfb;
filter:
progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff',
endColorstr='#e8e8e8');
background: -webkit-gradient(linear, left top, left bottom, from(#fff),
to(#e8e8e8)); background: -moz-linear-gradient(top, #fff, #e8e8e8);
}
Thanks.