i have a flickering problems in some computer and found that the problem is a vtips.css come with NT 12.35
p#vtip {
display:none;
position:absolute;
padding:10px;
left:5px;
font-size:1em;
background-color:white;
border:1px solid #a6c9e2;
border-radius:5px;
z-index:999999; <---- did not have a semicolon at the end
pointer-events: none; <-- added for prevent flickering
}
p#vtip #vtipArrow { position: absolute; top: -10px; left: 5px }