ToolTip is shown partially when the application is near the bottom of screen.

Steps to reproduce:
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1) Run SwingSet2 demo.
2) Go to toolTip Demo.
3) Take the SwingSet2 frame towards left side of the screen such that the "Cow" (Image of the Demo) is half visible and some portion of the frame is behind the taskbar.
4) Now place the mouse such that that the HTML tooltip appears.
5) Notice that the Tooltip is cut at the bottom.
Please see the the attached image for more clearification.

I have used 1.4.2_fcs_b28, I was able to reproduce the bug#4644444. I did not had 1.4.0_01, hopper, so was not able to verify on that build. Also I have used Tiger b59 , I was able to reproduce this.