Comment 6 for bug 877905

Having the same problem, I noticed it when Compiz wouldn't load.

sandy@sandy-laptop:~$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)

sandy@sandy-laptop:~$ glxinfo
name of display: :0.0
X Error of failed request: BadLength (poly request too large or internal Xlib length error)
  Major opcode of failed request: 153 (GLX)
  Minor opcode of failed request: 17 (X_GLXVendorPrivateWithReply)
  Serial number of failed request: 17
  Current serial number in output stream: 17

sandy@sandy-laptop:~$ compiz
compiz (core) - Fatal: Root visual is not a GL visual
compiz (core) - Error: Failed to manage screen: 0
compiz (core) - Fatal: No manageable screens found on display :0.0