NetBeans não executa programa

Bom pessoal eu tenho toda a minha telinha bonitinha soh que quando eu quero executar ela ele não mostra nada dos meus objetos além de jogar ela na parte esquerda superior do tamanho 20 por 20.

Ele joga esse erro aqui:

Locking assertion failure. Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb4c21767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb4c218b1]
#2 /usr/lib/libX11.so.6(_XReply+0xfd) [0x826711bd]
#3 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so [0x8294264e]
#4 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so [0x82920f97]
#5 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so [0x82921248]
#6 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so(Java_sun_awt_X11GraphicsEnvironment_initDisplay+0x2f) [0x8292154f]
#7 [0xb4cf8b7b]
#8 [0xb4cf0f0d]
#9 [0xb4cf0f0d]
#10 [0xb4cee243]
#11 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x62c5ecd]
#12 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x64523b8]
#13 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x62c5d60]
#14 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so(JVM_DoPrivileged+0x34b) [0x631bc1b]
#15 /opt/jdk1.6.0_03/jre/lib/i386/libjava.so(Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2+0x3d) [0xb7d0996d]
#16 [0xb4cf8b7b]
#17 [0xb4cf0da7]
#18 [0xb4cee243]
#19 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x62c5ecd]
Locking assertion failure. Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb4c21767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_lock+0x2e) [0xb4c2181e]
#2 /usr/lib/libX11.so.6 [0x82670518]
#3 /usr/lib/libX11.so.6(XGetVisualInfo+0x26) [0x826670a6]
#4 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so [0x82920249]
#5 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so [0x82920495]
#6 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so [0x829212f9]
#7 /opt/jdk1.6.0_03/jre/lib/i386/xawt/libmawt.so(Java_sun_awt_X11GraphicsEnvironment_initDisplay+0x2f) [0x8292154f]
#8 [0xb4cf8b7b]
#9 [0xb4cf0f0d]
#10 [0xb4cf0f0d]
#11 [0xb4cee243]
#12 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x62c5ecd]
#13 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x64523b8]
#14 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so [0x62c5d60]
#15 /opt/jdk1.6.0_03/jre/lib/i386/server/libjvm.so(JVM_DoPrivileged+0x34b) [0x631bc1b]
#16 /opt/jdk1.6.0_03/jre/lib/i386/libjava.so(Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2+0x3d) [0xb7d0996d]
#17 [0xb4cf8b7b]
#18 [0xb4cf0da7]
#19 [0xb4cee243]

Acontece com todas as aplicações? já tentou limpar o projeto? Flw

soh tenho uma tela por enquanto

já tentei limpar sim