If the first option didn't work, it's because your heights need to be a tiny bit smaller than you think. Try 1-2 px smaller and see if it works.
Originally Posted by cryoffalcon
Here's what I meant by invisible anchor- it'll give you the basic idea, I hope.
<a id="atooltip" name="tooltipbox" href="whateveryoucallyourtooltipbox">this is the text </a>that is near the end of the box but not necessarily at the end, so when you mouse over you can get your tooltip box...</p>