Occasionally, after an SVN update where POM's have changed, IntelliJ does not seem to notice this and you start having strange behaviors (non-existing classes, methods, ...). I know now that reimporting all maven projects fixes the issue but I don't understand why this is necessary.
I have checked 'Import Maven projects automatically'.
I don't think it's a bug since this was already the case in version 12 and still is in 13.