Looks like maybe a regression in the Subversion module. Repos are created owned by root:root, which makes them not work anymore. Ownership needs to be apache:apache if only Webmin and apache are allowed to mess with it, and domain_user:apache if the user should be able to directly work with it (if the latter, the group set ID bit needs to be set with g+sw, so they can't break it by accessing it directly). Possibly should be configurable.
Subversion repos owned by root