Have been using a simple CSS only tooltip.
Working Example css:
.tip
{
position:relative;
}
.tip span.tooltip
{
display:none;
background:#ff5112;
border:1px solid #9C0;
}
.tip:hover span.tooltip
{
display:block;
position:absolute;
top:2em; left:2em; width:15em;
border:1px solid #0cf;
background-color:#cff; color:#000;
text-align: center
}
html:
<span class="tip">
<table><tr>
<td>Working Tip</td><span class="tooltip">Tip</span>
</tr></table>
</span>
Not working example: html:
<table><tr>
<span class="tip"><td>Not working TIP</td><span class="tooltip">Tip</span></span>
</tr></table>
And a Live example