IE Issue w/ couple of pixels

Everything is fine if firefox 2 but in IE the right side gets pushed down.  If I widen the outer div it comes together but leaving a couple of pixels between the left and right.  Any Ideas....thanks

.portfolioCellHolder {margin: 0;padding: 0;width: 556px}
.holderRight {margin: 0;padding: 0;float: right;width: 380px}
.holderRightTop {margin: 0;padding: 0;width: 380px;height: 24px;background: url(../portfolio/images/holder_right_top.png) no-repeat}
.holderRightMiddle {margin: 0;padding: 0;width: 380px;height: 118px;background: url(../portfolio/images/holder_right_middle.png) repeat-y}
.holderRightBottom {margin: 0;padding: 0;width: 380px;height: 16px;background: url(../portfolio/images/holder_right_bottom.png) no-repeat}
.holderLeft {margin: 0;padding: 0;width: 176px}

<div class="portfolioCellHolder">
      <div class="holderRight">
            <div class="holderRightTop"></div>
            <div class="holderRightMiddle">
                  <div class="portfolioHolderText">
                        <h2>Lorem Ipsum</h2>
                        <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer.</p>
                        <ul>
                              <li><a class="portfolio" href="#">Lorem Ipsum</a></li>
                        </ul>
                  </div>
            </div>
            <div class="holderRightBottom"></div>
      </div>
      <div class="holderLeft">
            <img src="images/site_thumb.png" width="176" height="158" alt="" />
      </div>
</div><!--END Portfolio Cell Holder-->