This is in my case:
$ compiz --replace
GLX_EXT_texture_from_pixmap is available with direct rendering.
/usr/bin/gtk-window-decorator: Could not acquire decoration manager
selection on screen 0 display ":0.0"
/usr/bin/compiz.real: decoration: property ignored because version is
20061011 and decoration plugin version is 20070319
/usr/bin/compiz.real: decoration: property ignored because version is
20061011 and decoration plugin version is 20070319
/usr/bin/compiz.real: decoration: property ignored because version is
20061011 and decoration plugin version is 20070319
/usr/bin/compiz.real: Failed to load slide: freedesktop
Which compiz are you using? 0.5.0 is currently in unstable, it would be
good to test it.