I just installed 4.3.3 on my SuSE 9.1 machine at work (which also has JRE 1.5.0_01 but a different video card and -- obviously -- different drivers) and it had the same GUI corruption.

It looked ok until I tried to download something. So I think the code to add the download sub-window must be the source of the problem.

One thing that's different, and may be a clue, is that the Linux version acted like my windowed copy of LW was actually running full-screen, even though it wasn't. In other words, if I did maximize LW, then I could see the bottom controls. Re-windowing it 'lost' them. I checked this on my Windows machine though and it's not the same; still a mystery there.