We recently fixed a couple of issues with the jQuery edition of the product. Both were cosmetic and can be patched with simple additions to the css:

1) First, the zIndex of the vertical separator for locked columns is higher than the one for the popups. This causes it to bleed through the popups:

2) The close button of the popup is misplaced.

 

The fix to both these issues is simple: 

Just add the following to your css:

   
.ui-dialog{

       z-index:999;

}

.ui-dialog .ui-dialog-titlebar-close span{
    left: 0px;
    margin: 0px;
    top: 0px;
}

This will resolve both these issues: