[Xcb] xcb_xlib.c:50: xcb_xlib_unlock: Assertion `c->xlib.lock' failed.

[Kay Nettle]

I looked through the archive and saw that someone had posted about 
this problem with matlab.  I'm running X11R7.2, which I built myself, so
it maybe something I did, on a ubuntu box,  and I still have the 
problem.  Here is what I get doing 'matlab -Dgdb':

#0  0xb7fa2410 in __kernel_vsyscall ()
#1  0xb74a39a1 in raise () from /lib/tls/i686/cmov/libc.so.6
#2  0xb74a52b9 in abort () from /lib/tls/i686/cmov/libc.so.6
#3  0xb749cf51 in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#4  0xb5af7a30 in xcb_xlib_unlock (c=0x8740c88) at xcb_xlib.c:55
#5  0xb5e65f21 in _XReply (dpy=0x8730210, rep=0xbffc85f8, extra=0, discard=0)
    at xcb_io.c:364
#6  0xa16d326a in getAwtLockFunctions ()
   from /v/filer4b/software/matlab-r2007a/sys/java/jre/glnx86/jre1.5.0/lib/i386/xawt/libmawt.so
#7  0xa16b9352 in Java_sun_awt_X11GraphicsDevice_initIDs ()
   from /v/filer4b/software/matlab-r2007a/sys/java/jre/glnx86/jre1.5.0/lib/i386/xawt/libmawt.so
#8  0xa16b9599 in Java_sun_awt_X11GraphicsDevice_initIDs ()
   from /v/filer4b/software/matlab-r2007a/sys/java/jre/glnx86/jre1.5.0/lib/i386/xawt/libmawt.so
#9  0xa16b97a4 in Java_sun_awt_X11GraphicsEnvironment_initDisplay ()
   from /v/filer4b/software/matlab-r2007a/sys/java/jre/glnx86/jre1.5.0/lib/i386/xawt/libmawt.so
#10 0xadb0ab8b in ?? ()
#11 0x0811498c in ?? ()
#12 0xbffc883c in ?? ()
#13 0x00000001 in ?? ()
#14 0xaa140e30 in ?? ()
#15 0xbffc8810 in ?? ()
#16 0xaa13b3d0 in ?? ()
#17 0xbffc8840 in ?? ()
#18 0xaa141618 in ?? ()
#19 0x00000000 in ?? ()