Here is the weird problem: if you run the following sample, after you make popup visible, move frame to another place, you will see popup stays in the original place and does not disappear. This does not happen to Swing, but happens to code that uses SWT_AWT bridge.
I have seen several people in Eclipse forum asking this question, now I have the same problem. It seems that nobody has been able to answer this question so far. I am wondering if any SWT expert here can shed some light on it.