That bug has been opened on
https://launchpad.net/distros/ubuntu/+source/compiz/+bug/74012

"Hi,
my xserver is configured like this:
Section "ServerLayout"
    Identifier "Default Layout"
    Screen 0 "Default Screen" 0 0
    Screen 1 "TV" RightOf "Default Screen"
    InputDevice "Generic Keyboard"
    InputDevice "Configured Mouse"
EndSection

and when I start compiz 0.3.3-git on a clean feisty system it crashes. If I
comment out Screen 1, compiz works fine.
This is on AMD64.
...
http://librarian.launchpad.net/5421398/_usr_bin_compiz.real.1000.crash
Crashreport
...
Package: compiz-core 1:0.3.4-0ubuntu2
...
 Core was generated by `compiz.real --replace --use-cow gconf gconf'.
 Program terminated with signal 11, Segmentation fault.
 #0  0x00002b5bfc782deb in strstr () from /lib/libc.so.6
 #0  0x00002b5bfc782deb in strstr () from /lib/libc.so.6
 No symbol table info available.
 #1  0x0000000000414c67 in addScreen (display=0x62ce00, screenNum=1, 
     wmSnSelectionWindow=<value optimized out>, wmSnAtom=355, 
     wmSnTimestamp=2298889900) at screen.c:1690
 	s = <value optimized out>
 	dpy = (Display *) 0x6303e0
 	black = {pixel = 0, red = 0, green = 0, blue = 0, flags = 0 '\0', 
   pad = 0 '\0'}
 	bitmap = <value optimized out>
 	templ = {visual = 0x6303e0, visualid = 389, screen = 6489056, 
   depth = 0, class = 32, red_mask = 140736138024672, green_mask = 6489056, 
   blue_mask = 47674102198800, colormap_size = -66922513, bits_per_rgb = 11099}
 	visinfo = <value optimized out>
 	fbConfigs = <value optimized out>
 	rootReturn = 6489056
 	parentReturn = 355
 	children = <value optimized out>
 	nchildren = <value optimized out>
 	defaultDepth = 24
 	nvisinfo = 1
 	nElements = <value optimized out>
 	value = 1
 	i = <value optimized out>
 	glxExtensions = 0x6987f0 "GLX_EXT_visual_info GLX_EXT_visual_rating
GLX_SGIX_fbconfig GLX_SGIX_pbuffer GLX_SGI_video_sync GLX_SGI_swap_control
GLX_EXT_texture_from_pixmap GLX_ARB_multisample GLX_NV_float_buffer
GLX_ARB_fbconfi"...
 	glxServerExtensions = <value optimized out>
 	glExtensions = 0x0
 	stencilBits = <value optimized out>
 	attrib = {background_pixmap = 0, background_pixel = 0, 
   border_pixmap = 2944636400, border_pixel = 140736138024640, 
   bit_gravity = 0, win_gravity = 0, backing_store = 0, 
   backing_planes = 6492656, backing_pixel = 6489056, save_under = 62914704, 
   event_mask = 47674070059129, do_not_propagate_mask = 1, 
   override_redirect = 4194304, colormap = 4, cursor = 140736138024672}
 	globalAmbient = {0.100000001, 0.100000001, 0.100000001, 0.100000001}
 	ambientLight = {0, 0, 0, 0}
 	diffuseLight = {0.899999976, 0.899999976, 0.899999976, 0.899999976}
 	light0Position = {-0.5, 0.5, -9, 1}
 	w = <value optimized out>
 	shareList = <value optimized out>
 	data = 0 '\0'
...
This crashreport should have a working backtrace!"

corresponding code:

"...
    glExtensions = (const char *) glGetString (GL_EXTENSIONS);

    s->textureNonPowerOfTwo = 0;
    if (strstr (glExtensions, "GL_ARB_texture_non_power_of_two"))     
	s->textureNonPowerOfTwo = 1;
..."