Comment 4 for bug 1405867

"Thank you for your bug report. Is nautilus running and handling the desktop rendering?"

How do I tell? All I do is reboot and do System Settings > Appearance > Wallpaper > select and it doesn't change wallpaper until reboot. 14.10 works fine.

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=15.04
DISTRIB_CODENAME=vivid
DISTRIB_DESCRIPTION="Ubuntu Vivid Vervet (development branch)"
Linux Lenovo2 3.18.0-8-generic #9-Ubuntu SMP Mon Jan 5 22:51:10 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
model name : Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz
model name : Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz
00:02.0 VGA compatible controller: Intel Corporation 4 Series Chipset Integrated Graphics Controller (rev 03)

Thanks for any suggestions