Clean install not upgrade.
BTW,
…so don’t tell me no one has this problem.
I didn’t say that, as I mentioned I got the problem once before:. I also fixed it with a chmod, but I later followed the tip to use a local-repo and Yast for upgrade or clean install (i.e. not clicking on the rpm).
It was in the earlier of those two very long threads about USB not working in VBox. We did a lot of testing of different combinations which involved many installs of different releases. Using that method, I and others posting never had the permissions problem. 
Hmm i’ll try that. Thanks for the tip. Next time i’ll save the VirtualBox rpm in one folder which is set as a local repo 