For some reason we are still setting the desktop window background to None
for part of startup. It's baaaaack.
We (Red Hat) should try to fix this before next release.
Blah, I can't reproduce this anymore.
OK, only happens on startup, and the root window hints are not set; indicates a
bug in the background properties capplet most likely.
Building a fix in control-center-18.104.22.168-16
Fix appears to work in my testing