The Slick Grid Does Not Display At All (with tabs)

I'm having a similar issue (blank grid but data is available via JS), but only in IE (8). Chrome and FF are rendering just fine.

I am getting the following error in IE: "Object doesn't support this property or method" (slickgrid.tabs.js?luesqs, line 57 character 18)
Which is right around here:

55  $(columns).each(function(i, col) {
56                 if(typeof col.tab !== 'undefined'){
57 -->            if(tabs.indexOf(col.tab) === -1){
58                   $("<span class='slickgrid-tab' id='"+col.tab+"'>"+col.tab+"</span>").click(handleTabClick).appendTo($container);
59                   tabs.push(col.tab);
60                 }                                
61                }

I should note that I am displaying the tabs from within Slickgrids, and thats obviously part of the issue.

FYI - just confirmed that for me the display error is limited to IE and only when the view has tabs (through the slickgrid table settings)