Comment 2 for bug 193103

It happens to me on hardy and i386 as well. Here's the backtrace I get in the console:

Locking assertion failure. Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb54fa767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb54fa8b1]
#2 /usr/lib/libX11.so.6(_XReply+0xfd) [0xb554f29d]
#3 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/xawt/libmawt.so [0xb56508ce]
#4 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/xawt/libmawt.so [0xb562d067]
#5 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/xawt/libmawt.so [0xb562d318]
#6 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/xawt/libmawt.so(Java_sun_awt_X11GraphicsEnvironment_initDisplay+0x2f) [0xb562d61f]
#7 [0xb5cfaecd]
#8 [0xb5cf3edd]
#9 [0xb5cf3edd]
#10 [0xb5cf1249]
#11 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/client/libjvm.so [0x621c40d]
#12 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/client/libjvm.so [0x6310378]
#13 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/client/libjvm.so [0x621c2a0]
#14 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/client/libjvm.so(JVM_DoPrivileged+0x363) [0x6272153]
#15 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/libjava.so(Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2+0x3d) [0xb7d0c96d]
#16 [0xb5cfaecd]
#17 [0xb5cf3d77]
#18 [0xb5cf1249]
#19 /usr/lib/jvm/java-6-sun-1.6.0.04/jre/lib/i386/client/libjvm.so [0x621c40d]
java_vm: xcb_xlib.c:82: xcb_xlib_unlock: Assertion `c->xlib.lock' failed.
Could not read ack from child process
Plugin: Java VM process has died.
plugin: java process died due to signal 6
Could not start JavaVM!

VM did not start up properly