My Xorg was also blocking - only the mouse pointer keeps moving, but no other thing happends. I solved the problem (for now), by removing the comment for the option NoAccel and setting the value to true. I'm using the xorg.conf generated with Xorg -configure with just that change, and everything seem to be working. I'm even using the composite from xfce4 (for the real transparent xfce4-terminal), and it's working ok - maybe not as fast as with accelaration. For me it was very simple to reproduce the error. As soon as gdm was active (the default theme on debian - the one with the stars and the star rocket), a click on any menu would block everything but the mouse movement. Here is the log for my X when it was blocking. Anything else I can do to help solve this? X.Org X Server 1.9.4 Release Date: 2011-02-04 [ 147.356] X Protocol Version 11, Revision 0 [ 147.356] Build Operating System: Linux 2.6.32.28-dsa-ia32 i686 Debian [ 147.356] Current Operating System: Linux voyager 2.6.37-1-686 #1 SMP Tue Feb 15 18:21:50 UTC 2011 i686 [ 147.356] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-2.6.37-1-686 root=UUID=b69dfdff-c215-473f-9f91-1680b2773ef1 ro single [ 147.356] Build Date: 17 February 2011 01:25:01AM [ 147.356] xorg-server 2:1.9.4-2 (Cyril Brulebois