Hello,
I was able to install jswat (4.5) on Ubuntu (10.10), and the splash
screen appeared correctly, but the main window was empty (i.e.
completely grey).
It turns out that the solution was to set AWT_TOOLKIT=MToolkit, as
described in this thread:
http://ubuntuforums.org/showthread.php?t=784659
Perhaps this post will save other people some time.
Tim.