After upgrading from Xubuntu 14.04 to 14.10 some black signs appear on the windows.
$ dmidecode
...
System Information
Manufacturer: TOSHIBA
Product Name: Satellite Pro L350
...
$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
$ cat /var/log/Xorg.1.log | grep AIGLX
(II) AIGLX: Suspending AIGLX