Why the list of this Google Map Api disappears in Internet Explorer 7? (well, actually because is IE7, but how can I fix it?)

Question

The list in the left side of the page (the names of the cities) are correctly displayed in Firefox and Chrome (even IE8) but in IE7 and IE6 the list disappears.

Any suggestions?

http://ada.kiexpro.com/html/map.html

I'm not sure if there's a problem with the CSS but the Javascript that generates that list is the following:

function cm_loadMapJSON(json) {
  var usingRank = false;

  if(param_useSidebar == true) {
    var sidebarTD = document.createElement("td");
    sidebarTD.setAttribute("width","150");
    sidebarTD.setAttribute("valign","top");
    var sidebarDIV = document.createElement("div");
    sidebarDIV.id = "cm_sidebarDIV";
    sidebarDIV.style.overflow = "auto";
    sidebarDIV.style.height = "550px";
    sidebarDIV.style.fontSize = "14px";
    sidebarDIV.style.color = "#000000";
    sidebarTD.appendChild(sidebarDIV);
    document.getElementById("cm_mapTR").appendChild(sidebarTD);
  }