http://bugs.winehq.org/show_bug.cgi?id=27987
--- Comment #13 from Hans Leidekker hans@meelstraat.net 2012-01-05 03:34:40 CST --- A trace from wine 1.3.20 (last release before the introduction of rollback support) shows that custom action CA_BeginHelpTransaction creates that guid directory.
CA_BeginHelpTransaction is sequenced after CA_RollbackHelpTransaction though, so my quess is that we're not scheduling the actions correctly.