I've installed openproj from AUR and met the following issue: the program runs, but the main GUI window is blank (no buttons, menus - nothing), although the dialog windows appear normal. I don't have much experience with java, and tried both jre and openjdk6 - with the same result. Then I tried to run openproj without any window manager, and it worked! I noticed that openjdk6 warns: when you use a non-reparenting window manager set _JAVA_AWT_WM_NONREPARENTING=1 in /etc/profile.d/openjdk6.sh So the setting of that env. variable indeed helps with openjdk6, but not with jre.