LWJGL on Ubuntu 12.10 : Black desktop wallpaper

[mrgibson]

Tested with LWJGL 2.8.1 , 2.8.4, 2.8.5 and NIGHTLY BUILD:

java -cp .:res:jar/lwjgl.jar:jar/lwjgl_test.jar:jar/lwjgl_util.jar:jar/jinput.jar: -Djava.library.path=native/linux org.lwjgl.test.WindowCreationTest

When I close the window, the screen blink and I loose my desktop wallpaper (now plain black). Look like a part of Unity crash.

Some specs:
Ubuntu 12.10 64bits (Unity)
NVIDIA Proprietary Driver 304.60 with gf5600ti

Someone have a clue?