Here is the solution for rounded corners for IE:

1. Download the attached file (documentation code.google.com/p/curved-corner/ )

2. Unrar the file

3. Upload the file to your base.css directory (I uploaded it to the original /ow_themes/your_theme  and to the /ow_static/themes/your_theme directory)

4. Change the base.css in the above directories. For example:

.console_item{
    background: #fff url(images/consolebg.png) repeat-x center left;
    float:left;
    height:20px;
    margin:5px 0 0 5px;
    padding:0 5px;
    -moz-border-radius: 5px 5px 5px 5px;
    -webkit-border-radius: 5px 5px 5px 5px;
    border-radius: 5px;
    border: 0;
    border-top: 0;
    behavior:url(border-radius.htc);
}

Insert the bold sections.

5. Finished :) Now you have rounded corners without graphics in IE