If I do a show(); hide(); show() my AWT Frame disappears!

Yeah, so it seems. Using setVisible(true|false) does not seem to work either; the window just refuses to show up the second time. Actually it gets iconified in certain window managers, and you can probably find the window when you look into a window list. This problem does not occur on KDE1, but all other window managers exhibit this problem (including KDE2).

This is a known bug (bug number 4392518) in all Sun Linux JDKs up to 1.3.1, and might be fixed in JDK1.4. The workaround is to use dispose() instead of hide() or setVisible(

information here.