=== CSS files ===

zTreeStyle.css file:
#1 - original saved as zTreeStyle_source.css
#2 - in css file all attributes forced !important due to template overrides
#3 - definition 
    .ztree li span.button
        - added line (fix transition effect on hover or check) 
            -moz-transition: none !important;
            -transition: none !important;
            -webkit-transition: none !important;
    .ztree li span.button.chk
        - added line (fix transition effect on hover or check) 
            -moz-transition: none !important;
            -transition: none !important;
            -webkit-transition: none !important;
 
=== JS files ===

jquery.ztree.core.js
#1 === line 1360 ===
    - old value
        if (icon) icoStyle.push("background:url(", icon, ") 0 0 no-repeat;");
    - new value (added !important due to template overrides)
        if (icon) icoStyle.push("background:url(", icon, ") 0 0 no-repeat !important;");

#2 === line 1362 ===
    - old value
        icoStyle.push("display:none;");
    - new value (added !important due to template overrides)
        icoStyle.push("display:none !important;");